Linked Life Data

21684251

Source:http://linkedlifedata.com/resource/pubmed/id/21684251

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2011-8-12
pubmed:abstractText
Both the aa(3)-type cytochrome c oxidase from Rhodobacter sphaeroides (RsCcO(aa3)) and the closely related bo(3)-type ubiquinol oxidase from Escherichia coli (EcQO(bo3)) possess a proton-conducting D-channel that terminates at a glutamic acid, E286, which is critical for controlling proton transfer to the active site for oxygen chemistry and to a proton loading site for proton pumping. E286 mutations in each enzyme block proton flux and, therefore, inhibit oxidase function. In the current work, resonance Raman spectroscopy was used to show that the E286A and E286C mutations in RsCcO(aa3) result in long range conformational changes that influence the protein interactions with both heme a and heme a(3). Therefore, the severe reduction of the steady-state activity of the E286 mutants in RsCcO(aa3) to ~0.05% is not simply a result of the direct blockage of the D-channel, but it is also a consequence of the conformational changes induced by the mutations to heme a and to the heme a(3)-Cu(B) active site. In contrast, the E286C mutation of EcQO(bo3) exhibits no evidence of conformational changes at the two heme sites, indicating that its reduced activity (3%) is exclusively a result of the inhibition of proton transfer from the D-channel. We propose that in RsCcO(aa3), the E286 mutations severely perturb the active site through a close interaction with F282, which lies between E286 and the heme-copper active site. The local structure around E286 in EcQO(bo3) is different, providing a rationale for the very different effects of E286 mutations in the two enzymes. This article is part of a Special Issue entitled: Allosteric cooperativity in respiratory proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3002
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier B.V. All rights reserved.
pubmed:issnType
Print
pubmed:volume
1807
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1342-8
pubmed:meshHeading
pubmed-meshheading:21684251-Catalytic Domain, pubmed-meshheading:21684251-Copper, pubmed-meshheading:21684251-Cytochromes, pubmed-meshheading:21684251-Electron Transport, pubmed-meshheading:21684251-Electron Transport Complex IV, pubmed-meshheading:21684251-Escherichia coli, pubmed-meshheading:21684251-Escherichia coli Proteins, pubmed-meshheading:21684251-Glutamic Acid, pubmed-meshheading:21684251-Heme, pubmed-meshheading:21684251-Models, Molecular, pubmed-meshheading:21684251-Mutation, pubmed-meshheading:21684251-Oxidoreductases, pubmed-meshheading:21684251-Protein Binding, pubmed-meshheading:21684251-Protein Conformation, pubmed-meshheading:21684251-Protons, pubmed-meshheading:21684251-Rhodobacter sphaeroides, pubmed-meshheading:21684251-Species Specificity, pubmed-meshheading:21684251-Spectrum Analysis, Raman
pubmed:year
2011
pubmed:articleTitle
Differential effects of glutamate-286 mutations in the aa(3)-type cytochrome c oxidase from Rhodobacter sphaeroides and the cytochrome bo(3) ubiquinol oxidase from Escherichia coli.
pubmed:affiliation
Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural