3OUE

Structure of C-terminal hexaheme fragment of GSU1996

3OUE の概要

• エントリーDOI: 10.2210/pdb3oue/pdb
• 関連するPDBエントリー: 1hh5 1rwj 3bxu 3h33 3h34 3h4n 3OUQ 3OV0
• 分子名称: Cytochrome c family protein, SULFATE ION, HEME C, ... (4 entities in total)
• 機能のキーワード: multiheme cytochrome-c, electron transfer, fe reduction, geobacter sulfurreducens, cytochrome c7 (c3) fold, 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: 21192.20

構造登録者

Pokkuluri, P.R.,Schiffer, M. (登録日: 2010-09-14, 公開日: 2010-12-29, 最終更新日: 2024-10-30)

主引用文献

Pokkuluri, P.R.,Londer, Y.Y.,Duke, N.E.,Pessanha, M.,Yang, X.,Orshonsky, V.,Orshonsky, L.,Erickson, J.,Zagyanskiy, Y.,Salgueiro, C.A.,Schiffer, M.
Structure of a novel dodecaheme cytochrome c from Geobacter sulfurreducens reveals an extended 12nm protein with interacting hemes.
J.Struct.Biol., 174:223-233, 2011

PubMed Abstract: Multiheme cytochromes c are important in electron transfer pathways in reduction of both soluble and insoluble Fe(III) by Geobacter sulfurreducens. We determined the crystal structure at 3.2Å resolution of the first dodecaheme cytochrome c (GSU1996) along with its N-terminal and C-terminal hexaheme fragments at 2.6 and 2.15Å resolution, respectively. The macroscopic reduction potentials of the full-length protein and its fragments were measured. The sequence of GSU1996 can be divided into four c(7)-type domains (A, B, C and D) with homology to triheme cytochromes c(7). In cytochromes c(7) all three hemes are bis-His coordinated, whereas in c(7)-type domains the last heme is His-Met coordinated. The full-length GSU1996 has a 12nm long crescent shaped structure with the 12 hemes arranged along a polypeptide to form a "nanowire" of hemes; it has a modular structure. Surprisingly, while the C-terminal half of the protein consists of two separate c(7)-type domains (C and D) connected by a small linker, the N-terminal half of the protein has two c(7)-type domains (A and B) that form one structural unit. This is also observed in the AB fragment. There is an unexpected interaction between the hemes at the interface of domains A and B, which form a heme-pair with nearly parallel stacking of their porphyrin rings. The hemes adjacent to each other throughout the protein are within van der Waals distance which enables efficient electron exchange between them. For the first time, the structural details of c(7)-type domains from one multiheme protein were compared.

PubMed: 21130881
DOI: 10.1016/j.jsb.2010.11.022

実験手法

X-RAY DIFFRACTION (2.15 Å)