Dr. Allison C. Augustus-Wallace - Academia.edu (original) (raw)

Papers by Dr. Allison C. Augustus-Wallace

Journal of Biological Chemistry

ABSTRACTThe COVID-19 pandemic shut down undergraduate research programs across the U.S. Twenty-th... more ABSTRACTThe COVID-19 pandemic shut down undergraduate research programs across the U.S. Twenty-three sites offered remote undergraduate research programs in the life sciences during summer 2020. Given the unprecedented offering of remote research experiences, we carried out a study to describe and evaluate these programs. Using structured templates, we documented how programs were designed and implemented, including who participated. Through focus groups and surveys, we identified programmatic strengths and shortcomings as well as recommendations for improvements from the perspectives of participating students. Strengths included the quality of mentorship, opportunities for learning and professional development, and development of a sense of community. Weaknesses included limited cohort building, challenges with insufficient structure, and issues with technology. Although all programs had one or more activities related to diversity, equity, inclusion, and justice, these topics were ...

Journal of Interprofessional Care, 2020

Research within interprofessional education (IPE) indicates health professional students hold ste... more Research within interprofessional education (IPE) indicates health professional students hold stereotypes of other health professions at all stages within their academic journey. IPE can minimize negative stereotypes and influence a student's willingness and readiness to collaborate with others. This article explores undergraduate pre-health student stereotypes of various health professionals at the beginning and end of a six-week summer academic enrichment program, which included IPE. Convenience sampling was used to request participation in a survey, which included the Student Stereotypes Ratings Questionnaire (SSRQ). The SSRQ asks students to rate their perception of health professions on multiple traits. One hundred pre-health students across three institutions completed the SSRQ. The mean scores across all professions and all traits increased post-survey. Lowest pre-mean scores were for nursing (the ability to work independently and the ability to lead a team) and registered dietitian (the ability to lead a team). The highest pre-mean score was for the physician profession for academic ability. Results from this study indicate varying levels of stereotypes have already developed in pre-health students. After the six-week program, pre-health students' perceptions of health professions were positively affected. Data from this study indicates there are benefits to exposing pre-health students to IPE.

The FASEB Journal, Apr 1, 2011

Journal of Continuing Education in the Health Professions, 2013

The education of health care professionals has evolved from focusing on the individual practition... more The education of health care professionals has evolved from focusing on the individual practitioner's knowledge and skills to recognizing that high quality health care requires practitioners who are prepared to function in interprofessional teams. Higher education is heeding the call to prepare students to value teamwork and develop skills for working in interprofessional teams. While there is much written on implementing interprofessional education (IPE) in the practice setting and in larger institutions, there is little literature on implementing IPE within a university that is not affiliated with a medical school or medical center; which can be especially challenging. This article shares the many challenges to implementing IPE within this context and presents strategies one university used toward developing an integrated IPE program that is relevant to nine health-related disciplines.

ABSTRACTIn-person undergraduate research experiences (UREs) promote students’ integration into ca... more ABSTRACTIn-person undergraduate research experiences (UREs) promote students’ integration into careers in life science research. In 2020, the COVID-19 pandemic prompted institutions hosting summer URE programs to offer them remotely, raising questions about whether undergraduates who participate in remote research can experience scientific integration. To address this, we investigated indicators of scientific integration for students who participated in remote life science URE programs in summer 2020. We found that these students experienced gains in their scientific self-efficacy and scientific identity similar to results reported for in-person UREs. We also found that these students perceived high benefits and low costs of doing research at the outset of their programs, and their perceptions did not change despite the remote circumstances. Yet, their perceptions differed by program, indicating that programs differentially affected students’ perceptions of the costs of doing resear...

Health, Interprofessional Practice and Education, 2020

PURPOSE This study examines the group performance trajectories of athletic training and physical ... more PURPOSE This study examines the group performance trajectories of athletic training and physical therapy students as they engaged in case-based learning experiences over the course of a semester. METHODS We apply Tuckman and Jensen's (1977) model of group development which predicts a non-linear performance trend as groups progress through the stages of forming, storming, norming, performing, and adjourning. We also examine the extent to which performance trajectories differ between interprofessional and uniprofessional groups. RESULTS As predicted, results suggest a significant non-linear trajectory of group performance across case-study trials. Specifically, a significant cubic trajectory was observed, such that group performance was characterized by two inflections points over time. Although we observed raw mean differences in performance ratings between interprofessional and uniprofessional groups, no significant differences were found across trials. We offer some speculative explanations for why this occurred. CONCLUSION Ultimately, our findings provide insight to educators and practitioners regarding why and when groups may need additional support.

Advances in Physiology Education

As literature indicates, historic racism and implicit bias throughout academia have been profound... more As literature indicates, historic racism and implicit bias throughout academia have been profound metrics leading to a lack of diversity, as related to people from underrepresented groups according to race and ethnicity, among biomedical sciences graduate students in U.S. universities. Recognizing such challenges, a team of biomedical scientists and inclusivity educators developed and implemented a pilot training program within an academic health sciences center as an initial step to educate faculty and staff regarding their roles in the promotion of an inclusive academic environment, receptive to all students, including underrepresented students. The 3-h workshop included didactic modules, videos, teaching modules, and active attendee participation. Faculty and staff were presented common terminology and ways to promote the development of an inclusive and diverse academic workforce. Compared with pre-workshop, post-workshop survey results indicated a statistically significant impro...

The Journal of Biological Chemistry, 2017

The mechanism of Nedd4-2 has been quantitatively explored for the first time using biochemically ... more The mechanism of Nedd4-2 has been quantitatively explored for the first time using biochemically defined kinetic assays examining rates of 125I-polyubiquitin chain assembly as a functional readout. We demonstrate that Nedd4-2 exhibits broad specificity for E2 paralogs of the Ubc4/5 clade to assemble Lys63-linked polyubiquitin chains. Full-length Nedd4-2 catalyzes free 125I-polyubiquitin chain assembly by hyperbolic Michaelis–Menten kinetics with respect to Ubc5B∼ubiquitin thioester concentration (Km = 44 ± 6 nm; kcat = 0.020 ± 0.007 s−1) and substrate inhibition above 0.5 μm (Ki = 2.5 ± 1.3 μm) that tends to zero velocity, requiring ordered binding at two functionally distinct E2∼ubiquitin–binding sites. The Ubc5BC85A product analog non-competitively inhibits Nedd4-2 (Ki = 2.0 ± 0.5 μm), consistent with the presence of the second E2-binding site. In contrast, the isosteric Ubc5BC85S-ubiquitin oxyester substrate analog exhibits competitive inhibition at the high-affinity Site 1 (Ki =...

Advances in Physiology Education

As literature indicates, historic racism and implicit bias throughout academia have been profound... more As literature indicates, historic racism and implicit bias throughout academia have been profound metrics leading to a lack of diversity, as related to people from underrepresented groups according to race and ethnicity, among biomedical sciences graduate students in U.S. universities. Recognizing such challenges, a team of biomedical scientists and inclusivity educators developed and implemented a pilot training program within an academic health sciences center as an initial step to educate faculty and staff regarding their roles in the promotion of an inclusive academic environment, receptive to all students, including underrepresented students. The 3-h workshop included didactic modules, videos, teaching modules, and active attendee participation. Faculty and staff were presented common terminology and ways to promote the development of an inclusive and diverse academic workforce. Compared with pre-workshop, post-workshop survey results indicated a statistically significant impro...

Journal of Biological Chemistry

Edited by George N. DeMartino The mechanism of Nedd4-2 has been quantitatively explored for the f... more Edited by George N. DeMartino The mechanism of Nedd4-2 has been quantitatively explored for the first time using biochemically defined kinetic assays examining rates of 125 I-polyubiquitin chain assembly as a functional readout. We demonstrate that Nedd4-2 exhibits broad specificity for E2 paralogs of the Ubc4/5 clade to assemble Lys 63linked polyubiquitin chains. Full-length Nedd4-2 catalyzes free 125 I-polyubiquitin chain assembly by hyperbolic Michaelis-Menten kinetics with respect to Ubc5Bϳubiquitin thioester concentration (K m ‫؍‬ 44 ؎ 6 nM; k cat ‫؍‬ 0.020 ؎ 0.007 s ؊1) and substrate inhibition above 0.5 M (K i ‫؍‬ 2.5 ؎ 1.3 M) that tends to zero velocity, requiring ordered binding at two functionally distinct E2ϳubiquitin-binding sites. The Ubc5BC85A product analog non-competitively inhibits Nedd4-2 (K i ‫؍‬ 2.0 ؎ 0.5 M), consistent with the presence of the second E2-binding site. In contrast, the isosteric Ubc5BC85S-ubiquitin oxyester substrate analog exhibits competitive inhibition at the high-affinity Site 1 (K i ‫؍‬ 720 ؎ 340 nM) and non-essential activation at the loweraffinity Site 2 (K act ‫؍‬ 750 ؎ 260 nM). Additional studies utilizing Ubc5BF62A, defective in binding the canonical E2 site, demonstrate that the cryptic Site 1 is associated with thioester formation, whereas binding at the canonical site (Site 2) is associated with polyubiquitin chain elongation. Finally, previously described Ca 2؉-dependent C2 domain-mediated autoinhibition of Nedd4-2 is not observed under our reported experimental conditions. These studies collectively demonstrate that Nedd4-2 catalyzes polyubiquitin chain assembly by an ordered two-step mechanism requiring two dynamically linked E2ϳubiquitin-binding sites analogous to that recently reported for E6AP, the founding member of the Hect ligase family.

Journal of Biological Chemistry

Edited by George N. DeMartino The NEDD4-2 (neural precursor cell-expressed developmentally down-r... more Edited by George N. DeMartino The NEDD4-2 (neural precursor cell-expressed developmentally down-regulated 4-2) HECT ligase catalyzes polyubiquitin chain assembly by an ordered two-step mechanism requiring two functionally distinct E2ϳubiquitin-binding sites, analogous to the trimeric E6AP/UBE3A HECT ligase. This conserved catalytic mechanism suggests that NEDD4-2, and presumably all HECT ligases, requires oligomerization to catalyze polyubiquitin chain assembly. To explore this hypothesis, we examined the catalytic mechanism of NEDD4-2 through the use of biochemically defined kinetic assays examining rates of 125 I-labeled polyubiquitin chain assembly and biophysical techniques. The results from gel filtration chromatography and dynamic light-scattering analyses demonstrate for the first time that active NEDD4-2 is a trimer. Homology modeling to E6AP revealed that the predicted intersubunit interface has an absolutely conserved Phe-823, substitution of which destabilized the trimer and resulted in a >10 4-fold decrease in k cat for polyubiquitin chain assembly. The small-molecule Phe-823 mimic, N-acetylphenylalanyl-amide, acted as a noncompetitive inhibitor (K i ‫؍‬ 8 ؎ 1.2 mM) of polyubiquitin chain elongation by destabilizing the active trimer, suggesting a mechanism for therapeutically targeting HECT ligases. Additional kinetic experiments indicated that monomeric NEDD4-2 catalyzes only HECTϳubiquitin thioester formation and monoubiquitination, whereas polyubiquitin chain assembly requires NEDD4-2 oligomerization. These results provide evidence that the previously identified sites 1 and 2 of NEDD4-2 function in trans to support chain elongation, explicating the requirement for oligomerization. Finally, we identified a conserved catalytic ensemble comprising Glu-646 and Arg-604 that supports HECT-ubiquitin thioester exchange and isopeptide bond formation at the active-site Cys-922 of NEDD4-2.

Biophysical Journal, 2017

Phosphorylation is a ubiquitous post-translational modification that has been implicated in a myr... more Phosphorylation is a ubiquitous post-translational modification that has been implicated in a myriad of biological functions but the underlying mechanism of action can be unclear. Here we study the phosphorylation-induced partial unfolding reaction in Raf Kinase Inhibitory Protein (RKIP), a dual function protein that regulates key pathophysiological states including heart disease and cancer. RKIP transitions between inhibition of Raf/MAPK to activation of Protein Kinase A via phosphorylation of a serine on RKIP. We show by NMR and X-ray crystallography that switching is due to a 'theft' by the phosphoserine of a lysine involved in a salt bridge with a pair of carboxylic acids. The helical region containing the phosphorylation site remains intact whereas the region with the acidic groups unfolds, thereby switching RKIP's preferred binding partner. A database search finds candidates that have the same structural motif underlying the theft mechanism. Three of them, Bax (1), troponin I & C (2), and Early endosome antigen 1 (3), had been more extensively characterized by mutations, and the results can be explained by a salt-bridge theft. These findings identify a facile and evolutionarily accessible mechanism for reorganizing a salt bridge network with only a single mutation to trigger a functional switch. We anticipate that the salt-bridge theft mechanism can be identified in other proteins and complexes.

Journal of Biological Chemistry

ABSTRACTThe COVID-19 pandemic shut down undergraduate research programs across the U.S. Twenty-th... more ABSTRACTThe COVID-19 pandemic shut down undergraduate research programs across the U.S. Twenty-three sites offered remote undergraduate research programs in the life sciences during summer 2020. Given the unprecedented offering of remote research experiences, we carried out a study to describe and evaluate these programs. Using structured templates, we documented how programs were designed and implemented, including who participated. Through focus groups and surveys, we identified programmatic strengths and shortcomings as well as recommendations for improvements from the perspectives of participating students. Strengths included the quality of mentorship, opportunities for learning and professional development, and development of a sense of community. Weaknesses included limited cohort building, challenges with insufficient structure, and issues with technology. Although all programs had one or more activities related to diversity, equity, inclusion, and justice, these topics were ...

Journal of Interprofessional Care, 2020

Research within interprofessional education (IPE) indicates health professional students hold ste... more Research within interprofessional education (IPE) indicates health professional students hold stereotypes of other health professions at all stages within their academic journey. IPE can minimize negative stereotypes and influence a student's willingness and readiness to collaborate with others. This article explores undergraduate pre-health student stereotypes of various health professionals at the beginning and end of a six-week summer academic enrichment program, which included IPE. Convenience sampling was used to request participation in a survey, which included the Student Stereotypes Ratings Questionnaire (SSRQ). The SSRQ asks students to rate their perception of health professions on multiple traits. One hundred pre-health students across three institutions completed the SSRQ. The mean scores across all professions and all traits increased post-survey. Lowest pre-mean scores were for nursing (the ability to work independently and the ability to lead a team) and registered dietitian (the ability to lead a team). The highest pre-mean score was for the physician profession for academic ability. Results from this study indicate varying levels of stereotypes have already developed in pre-health students. After the six-week program, pre-health students' perceptions of health professions were positively affected. Data from this study indicates there are benefits to exposing pre-health students to IPE.

The FASEB Journal, Apr 1, 2011

Journal of Continuing Education in the Health Professions, 2013

The education of health care professionals has evolved from focusing on the individual practition... more The education of health care professionals has evolved from focusing on the individual practitioner's knowledge and skills to recognizing that high quality health care requires practitioners who are prepared to function in interprofessional teams. Higher education is heeding the call to prepare students to value teamwork and develop skills for working in interprofessional teams. While there is much written on implementing interprofessional education (IPE) in the practice setting and in larger institutions, there is little literature on implementing IPE within a university that is not affiliated with a medical school or medical center; which can be especially challenging. This article shares the many challenges to implementing IPE within this context and presents strategies one university used toward developing an integrated IPE program that is relevant to nine health-related disciplines.

ABSTRACTIn-person undergraduate research experiences (UREs) promote students’ integration into ca... more ABSTRACTIn-person undergraduate research experiences (UREs) promote students’ integration into careers in life science research. In 2020, the COVID-19 pandemic prompted institutions hosting summer URE programs to offer them remotely, raising questions about whether undergraduates who participate in remote research can experience scientific integration. To address this, we investigated indicators of scientific integration for students who participated in remote life science URE programs in summer 2020. We found that these students experienced gains in their scientific self-efficacy and scientific identity similar to results reported for in-person UREs. We also found that these students perceived high benefits and low costs of doing research at the outset of their programs, and their perceptions did not change despite the remote circumstances. Yet, their perceptions differed by program, indicating that programs differentially affected students’ perceptions of the costs of doing resear...

Health, Interprofessional Practice and Education, 2020

PURPOSE This study examines the group performance trajectories of athletic training and physical ... more PURPOSE This study examines the group performance trajectories of athletic training and physical therapy students as they engaged in case-based learning experiences over the course of a semester. METHODS We apply Tuckman and Jensen's (1977) model of group development which predicts a non-linear performance trend as groups progress through the stages of forming, storming, norming, performing, and adjourning. We also examine the extent to which performance trajectories differ between interprofessional and uniprofessional groups. RESULTS As predicted, results suggest a significant non-linear trajectory of group performance across case-study trials. Specifically, a significant cubic trajectory was observed, such that group performance was characterized by two inflections points over time. Although we observed raw mean differences in performance ratings between interprofessional and uniprofessional groups, no significant differences were found across trials. We offer some speculative explanations for why this occurred. CONCLUSION Ultimately, our findings provide insight to educators and practitioners regarding why and when groups may need additional support.

Advances in Physiology Education

As literature indicates, historic racism and implicit bias throughout academia have been profound... more As literature indicates, historic racism and implicit bias throughout academia have been profound metrics leading to a lack of diversity, as related to people from underrepresented groups according to race and ethnicity, among biomedical sciences graduate students in U.S. universities. Recognizing such challenges, a team of biomedical scientists and inclusivity educators developed and implemented a pilot training program within an academic health sciences center as an initial step to educate faculty and staff regarding their roles in the promotion of an inclusive academic environment, receptive to all students, including underrepresented students. The 3-h workshop included didactic modules, videos, teaching modules, and active attendee participation. Faculty and staff were presented common terminology and ways to promote the development of an inclusive and diverse academic workforce. Compared with pre-workshop, post-workshop survey results indicated a statistically significant impro...

The Journal of Biological Chemistry, 2017

The mechanism of Nedd4-2 has been quantitatively explored for the first time using biochemically ... more The mechanism of Nedd4-2 has been quantitatively explored for the first time using biochemically defined kinetic assays examining rates of 125I-polyubiquitin chain assembly as a functional readout. We demonstrate that Nedd4-2 exhibits broad specificity for E2 paralogs of the Ubc4/5 clade to assemble Lys63-linked polyubiquitin chains. Full-length Nedd4-2 catalyzes free 125I-polyubiquitin chain assembly by hyperbolic Michaelis–Menten kinetics with respect to Ubc5B∼ubiquitin thioester concentration (Km = 44 ± 6 nm; kcat = 0.020 ± 0.007 s−1) and substrate inhibition above 0.5 μm (Ki = 2.5 ± 1.3 μm) that tends to zero velocity, requiring ordered binding at two functionally distinct E2∼ubiquitin–binding sites. The Ubc5BC85A product analog non-competitively inhibits Nedd4-2 (Ki = 2.0 ± 0.5 μm), consistent with the presence of the second E2-binding site. In contrast, the isosteric Ubc5BC85S-ubiquitin oxyester substrate analog exhibits competitive inhibition at the high-affinity Site 1 (Ki =...

Advances in Physiology Education

As literature indicates, historic racism and implicit bias throughout academia have been profound... more As literature indicates, historic racism and implicit bias throughout academia have been profound metrics leading to a lack of diversity, as related to people from underrepresented groups according to race and ethnicity, among biomedical sciences graduate students in U.S. universities. Recognizing such challenges, a team of biomedical scientists and inclusivity educators developed and implemented a pilot training program within an academic health sciences center as an initial step to educate faculty and staff regarding their roles in the promotion of an inclusive academic environment, receptive to all students, including underrepresented students. The 3-h workshop included didactic modules, videos, teaching modules, and active attendee participation. Faculty and staff were presented common terminology and ways to promote the development of an inclusive and diverse academic workforce. Compared with pre-workshop, post-workshop survey results indicated a statistically significant impro...

Journal of Biological Chemistry

Edited by George N. DeMartino The mechanism of Nedd4-2 has been quantitatively explored for the f... more Edited by George N. DeMartino The mechanism of Nedd4-2 has been quantitatively explored for the first time using biochemically defined kinetic assays examining rates of 125 I-polyubiquitin chain assembly as a functional readout. We demonstrate that Nedd4-2 exhibits broad specificity for E2 paralogs of the Ubc4/5 clade to assemble Lys 63linked polyubiquitin chains. Full-length Nedd4-2 catalyzes free 125 I-polyubiquitin chain assembly by hyperbolic Michaelis-Menten kinetics with respect to Ubc5Bϳubiquitin thioester concentration (K m ‫؍‬ 44 ؎ 6 nM; k cat ‫؍‬ 0.020 ؎ 0.007 s ؊1) and substrate inhibition above 0.5 M (K i ‫؍‬ 2.5 ؎ 1.3 M) that tends to zero velocity, requiring ordered binding at two functionally distinct E2ϳubiquitin-binding sites. The Ubc5BC85A product analog non-competitively inhibits Nedd4-2 (K i ‫؍‬ 2.0 ؎ 0.5 M), consistent with the presence of the second E2-binding site. In contrast, the isosteric Ubc5BC85S-ubiquitin oxyester substrate analog exhibits competitive inhibition at the high-affinity Site 1 (K i ‫؍‬ 720 ؎ 340 nM) and non-essential activation at the loweraffinity Site 2 (K act ‫؍‬ 750 ؎ 260 nM). Additional studies utilizing Ubc5BF62A, defective in binding the canonical E2 site, demonstrate that the cryptic Site 1 is associated with thioester formation, whereas binding at the canonical site (Site 2) is associated with polyubiquitin chain elongation. Finally, previously described Ca 2؉-dependent C2 domain-mediated autoinhibition of Nedd4-2 is not observed under our reported experimental conditions. These studies collectively demonstrate that Nedd4-2 catalyzes polyubiquitin chain assembly by an ordered two-step mechanism requiring two dynamically linked E2ϳubiquitin-binding sites analogous to that recently reported for E6AP, the founding member of the Hect ligase family.

Journal of Biological Chemistry

Edited by George N. DeMartino The NEDD4-2 (neural precursor cell-expressed developmentally down-r... more Edited by George N. DeMartino The NEDD4-2 (neural precursor cell-expressed developmentally down-regulated 4-2) HECT ligase catalyzes polyubiquitin chain assembly by an ordered two-step mechanism requiring two functionally distinct E2ϳubiquitin-binding sites, analogous to the trimeric E6AP/UBE3A HECT ligase. This conserved catalytic mechanism suggests that NEDD4-2, and presumably all HECT ligases, requires oligomerization to catalyze polyubiquitin chain assembly. To explore this hypothesis, we examined the catalytic mechanism of NEDD4-2 through the use of biochemically defined kinetic assays examining rates of 125 I-labeled polyubiquitin chain assembly and biophysical techniques. The results from gel filtration chromatography and dynamic light-scattering analyses demonstrate for the first time that active NEDD4-2 is a trimer. Homology modeling to E6AP revealed that the predicted intersubunit interface has an absolutely conserved Phe-823, substitution of which destabilized the trimer and resulted in a >10 4-fold decrease in k cat for polyubiquitin chain assembly. The small-molecule Phe-823 mimic, N-acetylphenylalanyl-amide, acted as a noncompetitive inhibitor (K i ‫؍‬ 8 ؎ 1.2 mM) of polyubiquitin chain elongation by destabilizing the active trimer, suggesting a mechanism for therapeutically targeting HECT ligases. Additional kinetic experiments indicated that monomeric NEDD4-2 catalyzes only HECTϳubiquitin thioester formation and monoubiquitination, whereas polyubiquitin chain assembly requires NEDD4-2 oligomerization. These results provide evidence that the previously identified sites 1 and 2 of NEDD4-2 function in trans to support chain elongation, explicating the requirement for oligomerization. Finally, we identified a conserved catalytic ensemble comprising Glu-646 and Arg-604 that supports HECT-ubiquitin thioester exchange and isopeptide bond formation at the active-site Cys-922 of NEDD4-2.

Biophysical Journal, 2017

Phosphorylation is a ubiquitous post-translational modification that has been implicated in a myr... more Phosphorylation is a ubiquitous post-translational modification that has been implicated in a myriad of biological functions but the underlying mechanism of action can be unclear. Here we study the phosphorylation-induced partial unfolding reaction in Raf Kinase Inhibitory Protein (RKIP), a dual function protein that regulates key pathophysiological states including heart disease and cancer. RKIP transitions between inhibition of Raf/MAPK to activation of Protein Kinase A via phosphorylation of a serine on RKIP. We show by NMR and X-ray crystallography that switching is due to a 'theft' by the phosphoserine of a lysine involved in a salt bridge with a pair of carboxylic acids. The helical region containing the phosphorylation site remains intact whereas the region with the acidic groups unfolds, thereby switching RKIP's preferred binding partner. A database search finds candidates that have the same structural motif underlying the theft mechanism. Three of them, Bax (1), troponin I & C (2), and Early endosome antigen 1 (3), had been more extensively characterized by mutations, and the results can be explained by a salt-bridge theft. These findings identify a facile and evolutionarily accessible mechanism for reorganizing a salt bridge network with only a single mutation to trigger a functional switch. We anticipate that the salt-bridge theft mechanism can be identified in other proteins and complexes.