cytochrome bo3 ubiquinol oxidase activity => GO:0009486 / ubiquinol oxidase (H+-transporting) / cytochrome bo3 ubiquinol oxidase activity / aerobic electron transport chain / oxidoreductase activity, acting on diphenols and related substances as donors, oxygen as acceptor / cytochrome-c oxidase activity / electron transport coupled proton transport / : / ATP synthesis coupled electron transport / aerobic respiration ...cytochrome bo3 ubiquinol oxidase activity => GO:0009486 / ubiquinol oxidase (H+-transporting) / cytochrome bo3 ubiquinol oxidase activity / aerobic electron transport chain / oxidoreductase activity, acting on diphenols and related substances as donors, oxygen as acceptor / cytochrome-c oxidase activity / electron transport coupled proton transport / : / ATP synthesis coupled electron transport / aerobic respiration / membrane => GO:0016020 / copper ion binding / heme binding / plasma membrane 類似検索 - 分子機能
Cytochrome o ubiquinol oxidase, subunit III / Cytochrome o ubiquinol oxidase subunit IV / Cytochrome o ubiquinol oxidase, subunit I / Ubiquinol oxidase subunit III domain / Cytochrome C oxidase subunit IV, prokaryotes / COX aromatic rich motif / Prokaryotic Cytochrome C oxidase subunit IV / COX Aromatic Rich Motif / Cytochrome o ubiquinol oxidase subunit II / Ubiquinol oxidase subunit 2, cupredoxin domain ...Cytochrome o ubiquinol oxidase, subunit III / Cytochrome o ubiquinol oxidase subunit IV / Cytochrome o ubiquinol oxidase, subunit I / Ubiquinol oxidase subunit III domain / Cytochrome C oxidase subunit IV, prokaryotes / COX aromatic rich motif / Prokaryotic Cytochrome C oxidase subunit IV / COX Aromatic Rich Motif / Cytochrome o ubiquinol oxidase subunit II / Ubiquinol oxidase subunit 2, cupredoxin domain / Cytochrome c oxidase subunit III / Cytochrome c oxidase subunit III-like / Cytochrome c oxidase, subunit III, 4-helical bundle / Cytochrome c oxidase subunit III / Heme-copper oxidase subunit III family profile. / Cytochrome c oxidase subunit III-like superfamily / Cytochrome C oxidase subunit II, transmembrane domain / Cytochrome oxidase subunit II transmembrane region profile. / Cytochrome c/quinol oxidase subunit II / Cytochrome C oxidase subunit II, transmembrane domain superfamily / Cytochrome c oxidase, subunit I, copper-binding site / Heme-copper oxidase catalytic subunit, copper B binding region signature. / Cytochrome c oxidase-like, subunit I domain / Cytochrome oxidase subunit I profile. / Cytochrome c oxidase subunit I / Cytochrome c oxidase-like, subunit I superfamily / Cytochrome C and Quinol oxidase polypeptide I / Cytochrome C oxidase subunit II, periplasmic domain / Cytochrome c oxidase subunit II-like C-terminal / Cytochrome oxidase subunit II copper A binding domain profile. / Cupredoxin / Prokaryotic membrane lipoprotein lipid attachment site profile. 類似検索 - ドメイン・相同性
ジャーナル: Proc Natl Acad Sci U S A / 年: 2021 タイトル: Cryo-EM structures of cytochrome reveal bound phospholipids and ubiquinone-8 in a dynamic substrate binding site. 著者: Jiao Li / Long Han / Francesca Vallese / Ziqiao Ding / Sylvia K Choi / Sangjin Hong / Yanmei Luo / Bin Liu / Chun Kit Chan / Emad Tajkhorshid / Jiapeng Zhu / Oliver Clarke / Kai Zhang / Robert Gennis / 要旨: Two independent structures of the proton-pumping, respiratory cytochrome ubiquinol oxidase (cyt ) have been determined by cryogenic electron microscopy (cryo-EM) in styrene-maleic acid (SMA) ...Two independent structures of the proton-pumping, respiratory cytochrome ubiquinol oxidase (cyt ) have been determined by cryogenic electron microscopy (cryo-EM) in styrene-maleic acid (SMA) copolymer nanodiscs and in membrane scaffold protein (MSP) nanodiscs to 2.55- and 2.19-Å resolution, respectively. The structures include the metal redox centers (heme , heme , and Cu), the redox-active cross-linked histidine-tyrosine cofactor, and the internal water molecules in the proton-conducting D channel. Each structure also contains one equivalent of ubiquinone-8 (UQ8) in the substrate binding site as well as several phospholipid molecules. The isoprene side chain of UQ8 is clamped within a hydrophobic groove in subunit I by transmembrane helix TM0, which is only present in quinol oxidases and not in the closely related cytochrome oxidases. Both structures show carbonyl O1 of the UQ8 headgroup hydrogen bonded to D75 and R71 In both structures, residue H98 occupies two conformations. In conformation 1, H98 forms a hydrogen bond with carbonyl O4 of the UQ8 headgroup, but in conformation 2, the imidazole side chain of H98 has flipped to form a hydrogen bond with E14 at the N-terminal end of TM0. We propose that H98 dynamics facilitate proton transfer from ubiquinol to the periplasmic aqueous phase during oxidation of the substrate. Computational studies show that TM0 creates a channel, allowing access of water to the ubiquinol headgroup and to H98.