5xte
From Proteopedia
Cryo-EM structure of human respiratory complex III (cytochrome bc1 complex)
Structural highlights
Disease[QCR7_HUMAN] Isolated CoQ-cytochrome C reductase deficiency. The disease is caused by mutations affecting the gene represented in this entry. [CYB_HUMAN] Histiocytoid cardiomyopathy;Leber hereditary optic neuropathy;Isolated CoQ-cytochrome C reductase deficiency. Defects in MT-CYB are a rare cause of mitochondrial dysfunction underlying different myopathies. They include mitochondrial encephalomyopathy, hypertrophic cardiomyopathy (HCM), and sporadic mitochondrial myopathy (MM). In mitochondrial myopathy, exercise intolerance is the predominant symptom. Additional features include lactic acidosis, muscle weakness and/or myoglobinuria. Defects in MTCYB are also found in cases of exercise intolerance accompanied by deafness, mental retardation, retinitis pigmentosa, cataract, growth retardation, epilepsy (multisystem disorder).[1] [2] The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting distinct genetic loci, including the gene represented in this entry. [CY1_HUMAN] Isolated CoQ-cytochrome C reductase deficiency. The disease is caused by mutations affecting the gene represented in this entry. [QCR8_HUMAN] Isolated CoQ-cytochrome C reductase deficiency. The disease is caused by mutations affecting the gene represented in this entry. [QCR2_HUMAN] Isolated CoQ-cytochrome C reductase deficiency. The disease is caused by mutations affecting the gene represented in this entry. Function[QCR7_HUMAN] This is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. This component is involved in redox-linked proton pumping. [QCR1_HUMAN] This is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. This protein may mediate formation of the complex between cytochromes c and c1. [UCRI_HUMAN] Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is a respiratory chain that generates an electrochemical potential coupled to ATP synthesis. The transit peptide of the Rieske protein seems to form part of the bc1 complex and is considered to be the subunit 11/IX of that complex. [QCR10_HUMAN] This is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. This protein may be closely linked to the iron-sulfur protein in the complex and function as an iron-sulfur protein binding factor. [CYB_HUMAN] Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex) that is part of the mitochondrial respiratory chain. The b-c1 complex mediates electron transfer from ubiquinol to cytochrome c. Contributes to the generation of a proton gradient across the mitochondrial membrane that is then used for ATP synthesis.[UniProtKB:P00157] [CY1_HUMAN] This is the heme-containing component of the cytochrome b-c1 complex, which accepts electrons from Rieske protein and transfers electrons to cytochrome c in the mitochondrial respiratory chain. [QCR8_HUMAN] This is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. This subunit, together with cytochrome b, binds to ubiquinone. [QCR9_HUMAN] This is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. This subunit interacts with cytochrome c1 (By similarity). [QCR2_HUMAN] This is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. The core protein 2 is required for the assembly of the complex. [QCR6_HUMAN] This is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. This protein may mediate formation of the complex between cytochromes c and c1. Publication Abstract from PubMedThe respiratory megacomplex represents the highest-order assembly of respiratory chain complexes, and it allows mitochondria to respond to energy-requiring conditions. To understand its architecture, we examined the human respiratory chain megacomplex-I2III2IV2 (MCI2III2IV2) with 140 subunits and a subset of associated cofactors using cryo-electron microscopy. The MCI2III2IV2 forms a circular structure with the dimeric CIII located in the center, where it is surrounded by two copies each of CI and CIV. Two cytochrome c (Cyt.c) molecules are positioned to accept electrons on the surface of the c1 state CIII dimer. Analyses indicate that CII could insert into the gaps between CI and CIV to form a closed ring, which we termed the electron transport chain supercomplex. The structure not only reveals the precise assignment of individual subunits of human CI and CIII, but also enables future in-depth analysis of the electron transport chain as a whole. Architecture of Human Mitochondrial Respiratory Megacomplex I2III2IV2.,Guo R, Zong S, Wu M, Gu J, Yang M Cell. 2017 Sep 7;170(6):1247-1257.e12. doi: 10.1016/j.cell.2017.07.050. Epub 2017, Aug 24. PMID:28844695[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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