Linked Life Data

21539785

Source:http://linkedlifedata.com/resource/pubmed/id/21539785

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2011-5-4
pubmed:abstractText
The phototaxis receptor sensory rhodopsin I (SRI) exists in two protein conformations, each of which is converted to the other by light absorption by the protein's retinylidene chromophore. One conformer inhibits a histidine-kinase attached to its bound transducer HtrI and its formation induces attractant motility responses, whereas the other conformer activates the kinase and its formation induces repellent responses. We performed Fourier transform infrared spectroscopy with temperature, pH, and mutation-induced shifts in the conformer equilibrium, and found that both conformers when present in the unphotolyzed dark state contain an all-trans retinal configuration that is photoisomerized to 13-cis, i.e., the same photoisomerization causes the opposite conformational change in the photointerconvertible pair of conformers depending on which conformer is present in the dark. Therefore, switching between the protein global conformations that define the two conformers is independent of the direction of isomerization. Insights into this phenomenon are gained from analysis of the evolution of the receptor from light-driven proton pumps, which use similar conformers for transport. The versatility of the conformational changes of microbial rhodopsins, including conformer interexchangeability in the photocycle as shown here, is likely a significant factor in the evolution of the diverse functionality of this protein family.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1542-0086
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
4
pubmed:volume
100
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2178-83
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Sensory rhodopsin-I as a bidirectional switch: opposite conformational changes from the same photoisomerization.
pubmed:affiliation
Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston, Texas, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural