title: Structural composition of alternative complex III: variations on the same theme.
abstract: Alternative complex III forms a recently identified family of enzymes with quinol:electron acceptor oxidoreductase activity. First biochemical and genomic analyses showed that ACIII is composed of six to eight subunits, most of which homologous to different proteins or domains already observed in other known enzymatic complexes. The increasing number of completely sequenced genomes led us to perform a new search for the genes coding for the different ACIII subunits. We have identified a larger number of gene clusters coding for ACIII, still confined to the bacterial domain, but extended to classes in which it was not observed before. We also found an unanticipated diversity in gene clusters, both in terms of its constitution and organization. The several unexpected gene arrangements brought new perspectives to the role of the different subunits of ACIII, namely in quinone binding and in proton translocation. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.
authors: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal.
authors: Patrícia N
authors: PN
authors: Refojo
authors: Miguel A
authors: MA
authors: Ribeiro
authors: Filipa
authors: F
authors: Calisto
authors: Miguel
authors: M
authors: Teixeira
authors: Manuela M
authors: MM
authors: Pereira
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D014450:Electron Transport Complex III / Q000235:genetics* / Q000378:metabolism; D023061:Gene Order; D005810:Multigene Family; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D014450:Electron Transport Complex III
keywords: ACIII; Alternative complex III; CISM; CISM family; Heme copper oxygen reductase; Rhodothermus marinus; alternative complex III; complex iron sulfur molybdoenzyme