그람 양성균의 Apo-form와 Holo-form의 구조적 분석

Abstract

We report the X-ray crystal structures of Gram-positive Fur proteins in both apo-form (Bacillus subtilis Fur) and Mn holo-form (Staphylococcus aureus Fur) solved by SAD (single anomalous diffraction) method. X-ray fluorescence scanning and diffraction data analysis indicate that the Mn holo-form contains 3 metals (Zn at Site 1, Mn at Site2 and Mn at Site3) per monomer and adopts a canonical closed V-shape dimeric conformation as reported previously for other DNA-binding competent Fur family proteins. Unexpectedly, the apo-form, containing only the structural Zn at Site 1, also adopts a closed V-shape dimeric conformation, but with slightly distorted orientations of DNA-binding domains. Furthermore, we solved the structure of the Zn holo-form (Zn at Site 1, Zn at Site2 and Zn at Site3) of S. aureus Fur. Despite the difference in metal coordination at Site 2 and 3, the overall structure of Zn holo-form is identical to that of Mn-holo form suggesting that Zn can also be used as a corepressor for Fur.diffraction data analysis indicate that the Mn holo-form contains 3 metals (Zn at Site 1, Mn at Site2 and Mn at Site3) per monomer and adopts a canonical closed V-shape dimeric conformation as reported previously for other DNA-binding competent Fur family proteins. Unexpectedly, the apo-form, containing only the structural Zn at Site 1, also adopts a closed V-shape dimeric conformation, but with slightly distorted orientations of DNA-binding domains. Furthermore, we solved the structure of the Zn holo-form (Zn at Site 1, Zn at Site2 and Zn at Site3) of S. aureus Fur. Despite the difference in metal coordination at Site 2 and 3, the overall structure of Zn holo-form is identical to that of Mn-holo form suggesting that Zn can also be used as a corepressor for Fur.