8QJG

Crystal structure of cytochrome domain 2 from PgcA

8QJG の概要

• エントリーDOI: 10.2210/pdb8qjg/pdb
• 関連するPDBエントリー: 8QJ6
• 分子名称: Lipoprotein cytochrome c, SULFATE ION, HEME C, ... (5 entities in total)
• 機能のキーワード: geobacter sulfurreducens, cytochrome, extracellular electron transfer, mineral reduction., electron transport
• 由来する生物種: Geobacter sulfurreducens PCA
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 64891.06

構造登録者

Nash, B.W.,Edwards, M.J.,Clarke, T.A. (登録日: 2023-09-13, 公開日: 2024-11-06)

主引用文献

Nash, B.W.,Fernandes, T.M.,Burton, J.A.J.,Morgado, L.,van Wonderen, J.H.,Svistunenko, D.A.,Edwards, M.J.,Salgueiro, C.A.,Butt, J.N.,Clarke, T.A.
Tethered heme domains in a triheme cytochrome allow for increased electron transport distances.
Protein Sci., 33:e5200-e5200, 2024

PubMed Abstract: Decades of research describe myriad redox enzymes that contain cofactors arranged in tightly packed chains facilitating rapid and controlled intra-protein electron transfer. Many such enzymes participate in extracellular electron transfer (EET), a process which allows microorganisms to conserve energy in anoxic environments by exploiting mineral oxides and other extracellular substrates as terminal electron acceptors. In this work, we describe the properties of the triheme cytochrome PgcA from Geobacter sulfurreducens. PgcA has been shown to play an important role in EET but is unusual in containing three CXXCH heme binding motifs that are separated by repeated (PT) motifs, suggested to enhance binding to mineral surfaces. Using a combination of structural, electrochemical, and biophysical techniques, we experimentally demonstrate that PgcA adopts numerous conformations stretching as far as 180 Å between the ends of domains I and III, without a tightly packed cofactor chain. Furthermore, we demonstrate a distinct role for its domain III as a mineral reductase that is recharged by domains I and II. These findings show PgcA to be the first of a new class of electron transfer proteins, with redox centers separated by some nanometers but tethered together by flexible linkers, facilitating electron transfer through a tethered diffusion mechanism rather than a fixed, closely packed electron transfer chain.

PubMed: 39470321
DOI: 10.1002/pro.5200

実験手法

X-RAY DIFFRACTION (1.8 Å)