2MZ9

Solution structure of oxidized triheme cytochrome PpcA from Geobacter sulfurreducens

2MZ9 の概要

• エントリーDOI: 10.2210/pdb2mz9/pdb
• NMR情報: BMRB: 25477
• 分子名称: PpcA, HEME C (2 entities in total)
• 機能のキーワード: cytochrome, paramagnetic, electron transport
• 由来する生物種: Geobacter sulfurreducens
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 9603.66

構造登録者

Morgado, L.,Bruix, M.,Pokkuluri, R.,Salgueiro, C.A.,Turner, D.L. (登録日: 2015-02-08, 公開日: 2016-02-10, 最終更新日: 2024-05-01)

主引用文献

Morgado, L.,Bruix, M.,Pokkuluri, P.R.,Salgueiro, C.A.,Turner, D.L.
Redox- and pH-linked conformational changes in triheme cytochrome PpcA from Geobacter sulfurreducens.
Biochem. J., 474:231-246, 2017

PubMed Abstract: The periplasmic triheme cytochrome PpcA from Geobacter sulfurreducens is highly abundant; it is the likely reservoir of electrons to the outer surface to assist the reduction of extracellular terminal acceptors; these include insoluble metal oxides in natural habitats and electrode surfaces from which electricity can be harvested. A detailed thermodynamic characterization of PpcA showed that it has an important redox-Bohr effect that might implicate the protein in e/H coupling mechanisms to sustain cellular growth. This functional mechanism requires control of both the redox state and the protonation state. In the present study, isotope-labeled PpcA was produced and the three-dimensional structure of PpcA in the oxidized form was determined by NMR. This is the first solution structure of a G. sulfurreducens cytochrome in the oxidized state. The comparison of oxidized and reduced structures revealed that the heme I axial ligand geometry changed and there were other significant changes in the segments near heme I. The pH-linked conformational rearrangements observed in the vicinity of the redox-Bohr center, both in the oxidized and reduced structures, constitute the structural basis for the differences observed in the pK values of the redox-Bohr center, providing insights into the e/H coupling molecular mechanisms driven by PpcA in G. sulfurreducens.

PubMed: 28062839
DOI: 10.1042/BCJ20160932

実験手法

SOLUTION NMR