Targeting of the FYVE domain to endosomal membranes is regulated by a histidine switch - PubMed (original) (raw)

Fig. 3.

Affinity for PtdIns(3)P increases in acidic media. (A) Superimposed 1H-15N HSQC spectra of the FYVE domain recorded during addition of PtdIns(3)P at pH values 6.0, 7.4, and 8.0. The relative concentrations of the 15N-labeled FYVE domain and PtdIns(3)P (Inset) are color-coded. (B–E) The binding curves used to calculate affinities for PtdIns(3)P based on changes in 1H and 15N resonances of the FYVE domain are shown and colored (B) in purple, red, green, orange, blue, brown, and cyan for 15N resonances (N) of Asn1352, His1372, Ala1349, Asp1351, Arg1369, and 1H resonances (H) of Ala1349 and Asp1351; (C) in purple, orange, green, brown, and blue for N of His1372, Asp1351, Arg1369, and H of Asp1351 and Arg1369; (D) in purple, green, red, orange, blue, cyan, brown, and magenta for N of Asn1352, Ala1349, His1372, Asp1351, Arg1369, and H of Asp1351, Ala1349, and Arg1369; and (E) in purple, orange, green, red, cyan, blue, brown, and magenta for N of His1371, Asn1352, Ala1349, His1372, and H of His1371, Ala1349, His1372, and Asn1352, respectively. (F) A graph summarizes the dependence of _K_d on pH.