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Papers by Geula Davidov
PLOS Neglected Tropical Diseases, Mar 24, 2021
Acta crystallographica, Jul 31, 2012
All of the supplemental figures are omitted from the list of Supporting Information. Please view ... more All of the supplemental figures are omitted from the list of Supporting Information. Please view the correct S1, S2, S3 and S4 Figs below. Supporting Information S1 Fig. Oligomeric state of purified MamAΔ41 according to size exclusion (Superdex 200) chromatograms from different species. Elution profiles of MamAΔ41 triple mutant from Desulfovibrio magneticus (RS-1) and wild type MamAΔ41 from Desulfovibrio magneticus (RS-1),M.magneticum (AMB-1),M.gryphiswaldense (MSR-1) and Candidatus Magnetobacterium bavaricum (Mbav) colored in light blue, green, red, orange and blue, respectively. Wild type MamAΔ41 from RS-1 eluted in a volume corresponds to octamer (~192 kDa) whereas the tri-ple mutated MamAΔ41 eluted in three separate peaks that correspond to a 13-monomer oligo-mer (~312 kDa), octamer (~192 kDa) and a monomer ( ~ 24 kDa). Both MamAΔ41 from AMB-1 and Mbav eluted at a volume corresponding to the monomer (20–22 kDa). MamAΔ41 fromMSR-1 eluted at a volume typical of the trimer (~60 kDa...
Acta crystallographica. Section F, Structural biology and crystallization communications, 2012
MamM is a unique magnetosome-associated protein that shares substantial homology with cation diff... more MamM is a unique magnetosome-associated protein that shares substantial homology with cation diffusion facilitator (CDF) proteins, a group of heavy-metal-ion efflux transporters that participate in metal-ion homeostasis in all domains of life. Magnetotactic bacteria utilize CDF proteins in iron-oxide biomineralization and in magnetosome formation. Here, the crystallization and preliminary X-ray analysis of recombinant Magnetospirillum gryphiswaldense MamM is reported. The C-terminal domain of MamM was crystallized in the orthorhombic space group C222(1), with unit-cell parameters a = 37.1, b = 94.0, c = 53.3 Å. X-ray diffraction data were collected to a resolution of 2.0 Å.
Cellular and Molecular Life Sciences, 2021
Two modes of motility have been reported for bi-directional kinesin-5 motors: (a) context-depende... more Two modes of motility have been reported for bi-directional kinesin-5 motors: (a) context-dependent directionality reversal, a mode in which motors undergo persistent minus-end directed motility at the single-molecule level and switch to plus-end directed motility in different assays or under different conditions, such as during MT gliding or antiparallel sliding or as a function of motor clustering; and (b) bi-directional motility, defined as movement in two directions in the same assay, without persistent unidirectional motility. Here, we examine how modulation of motor-microtubule (MT) interactions affects these two modes of motility for the bi-directional kinesin-5, Cin8. We report that the large insert in loop 8 (L8) within the motor domain of Cin8 increases the MT affinity of Cin8 in vivo and in vitro and is required for Cin8 intracellular functions. We consistently found that recombinant purified L8 directly binds MTs and L8 induces single Cin8 motors to behave according to context-dependent directionality reversal and bi-directional motility modes at intermediate ionic strength and according to a bi-directional motility mode in an MT surface-gliding assay under low motor density conditions. We propose that the largely unstructured L8 facilitates flexible anchoring of Cin8 to the MTs. This flexible anchoring enables the direct observation of bi-directional motility in motility assays. Remarkably, although L8-deleted Cin8 variants exhibit a strong minus-end directed bias at the single-molecule level, they also exhibit plus-end directed motility in an MT-gliding assay. Thus, L8-induced flexible MT anchoring is required for bi-directional motility of single Cin8 molecules but is not necessary for context-dependent directionality reversal of Cin8 in an MT-gliding assay.
PLOS Neglected Tropical Diseases, Mar 24, 2021
Acta crystallographica, Jul 31, 2012
All of the supplemental figures are omitted from the list of Supporting Information. Please view ... more All of the supplemental figures are omitted from the list of Supporting Information. Please view the correct S1, S2, S3 and S4 Figs below. Supporting Information S1 Fig. Oligomeric state of purified MamAΔ41 according to size exclusion (Superdex 200) chromatograms from different species. Elution profiles of MamAΔ41 triple mutant from Desulfovibrio magneticus (RS-1) and wild type MamAΔ41 from Desulfovibrio magneticus (RS-1),M.magneticum (AMB-1),M.gryphiswaldense (MSR-1) and Candidatus Magnetobacterium bavaricum (Mbav) colored in light blue, green, red, orange and blue, respectively. Wild type MamAΔ41 from RS-1 eluted in a volume corresponds to octamer (~192 kDa) whereas the tri-ple mutated MamAΔ41 eluted in three separate peaks that correspond to a 13-monomer oligo-mer (~312 kDa), octamer (~192 kDa) and a monomer ( ~ 24 kDa). Both MamAΔ41 from AMB-1 and Mbav eluted at a volume corresponding to the monomer (20–22 kDa). MamAΔ41 fromMSR-1 eluted at a volume typical of the trimer (~60 kDa...
Acta crystallographica. Section F, Structural biology and crystallization communications, 2012
MamM is a unique magnetosome-associated protein that shares substantial homology with cation diff... more MamM is a unique magnetosome-associated protein that shares substantial homology with cation diffusion facilitator (CDF) proteins, a group of heavy-metal-ion efflux transporters that participate in metal-ion homeostasis in all domains of life. Magnetotactic bacteria utilize CDF proteins in iron-oxide biomineralization and in magnetosome formation. Here, the crystallization and preliminary X-ray analysis of recombinant Magnetospirillum gryphiswaldense MamM is reported. The C-terminal domain of MamM was crystallized in the orthorhombic space group C222(1), with unit-cell parameters a = 37.1, b = 94.0, c = 53.3 Å. X-ray diffraction data were collected to a resolution of 2.0 Å.
Cellular and Molecular Life Sciences, 2021
Two modes of motility have been reported for bi-directional kinesin-5 motors: (a) context-depende... more Two modes of motility have been reported for bi-directional kinesin-5 motors: (a) context-dependent directionality reversal, a mode in which motors undergo persistent minus-end directed motility at the single-molecule level and switch to plus-end directed motility in different assays or under different conditions, such as during MT gliding or antiparallel sliding or as a function of motor clustering; and (b) bi-directional motility, defined as movement in two directions in the same assay, without persistent unidirectional motility. Here, we examine how modulation of motor-microtubule (MT) interactions affects these two modes of motility for the bi-directional kinesin-5, Cin8. We report that the large insert in loop 8 (L8) within the motor domain of Cin8 increases the MT affinity of Cin8 in vivo and in vitro and is required for Cin8 intracellular functions. We consistently found that recombinant purified L8 directly binds MTs and L8 induces single Cin8 motors to behave according to context-dependent directionality reversal and bi-directional motility modes at intermediate ionic strength and according to a bi-directional motility mode in an MT surface-gliding assay under low motor density conditions. We propose that the largely unstructured L8 facilitates flexible anchoring of Cin8 to the MTs. This flexible anchoring enables the direct observation of bi-directional motility in motility assays. Remarkably, although L8-deleted Cin8 variants exhibit a strong minus-end directed bias at the single-molecule level, they also exhibit plus-end directed motility in an MT-gliding assay. Thus, L8-induced flexible MT anchoring is required for bi-directional motility of single Cin8 molecules but is not necessary for context-dependent directionality reversal of Cin8 in an MT-gliding assay.