Linked Life Data

10984603

Source:http://linkedlifedata.com/resource/pubmed/id/10984603

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-11-3
pubmed:abstractText
The study of light-induced proton transfers in the archaeal sensory rhodopsins (SR), phototaxis receptors in Halobacterium salinarum, has contributed important insights into their mechanism of signaling to their cognate transducer subunits in the signaling complex. Essential features of the bacteriorhodopsin (BR) pumping mechanism have been conserved in the evolution of the sensors, which carry out light-driven electrogenic proton transport when their transducers are removed. The interaction of SRI with its transducer blocks proton-conducting channels in the receptor thereby inhibiting its proton pumping, indicating that the pump machinery, rather than the transport activity itself, is functionally important for signaling. Analysis of SRII mutants has shown that the salt bridge between the protonated Schiff base and its counterion Asp73 constrains the receptor in its inactive conformation. Similarly, in BR, the corresponding salt bridge between the protonated Schiff base and Asp85 contributes to constraining the protein in a conformation in which its cytoplasmic channel is closed. Transducer chimera studies further indicate that the receptor conformational changes are transmitted from the sensors to their cognate transducers through transmembrane helix-helix interaction. These and other results reviewed here support a signaling mechanism in which tilting of helices on the cytoplasmic side (primarily outward tilting of helix F), similar to that which occurs in BR in its open cytoplasmic channel conformation, causes structural alterations in the transducer transmembrane helices.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
1460
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
230-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Proton transport by sensory rhodopsins and its modulation by transducer-binding.
pubmed:affiliation
Department of Space and Earth Science, Osaka University, Osaka 560-0043, Japan.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't