Linked Life Data

20643145

Source:http://linkedlifedata.com/resource/pubmed/id/20643145

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2010-8-30
pubmed:abstractText
Small multidrug resistance (SMR) transport proteins provide a model for the evolution of larger two-domain transport proteins. The orientation in the membrane of 27 proteins from the SMR family was determined using the reporter fusion technique. Nine members were encoded monocistronically (singles) and shown to insert in both orientations (dual topology). Eighteen members were encoded in pairs on the chromosome and shown to insert in fixed orientations; the two proteins in each pair invariably had opposite orientations in the membrane. Interaction between the two proteins in pairs was demonstrated by copurification. The orientation in the membrane of either protein in the pair was affected only marginally by the presence of the other protein. For the proteins in pairs, the orientation in the membrane correlated well with the distribution of positively charges residues (R+K) over the cytoplasmic and extracellular loops (positive-inside rule). In contrast, dual-topology insertion of the singles was predicted less well by the positive-inside rule. Three singles were predicted to insert in a single orientation with the N-terminus and the C-terminus at the extracellular side of the membrane. Analysis of charge distributions suggests the requirement of a threshold number of charges in the cytoplasmic loops for the positive-inside rule to be of predictive value. It is concluded that a combined analysis of gene organization on the chromosome and phylogeny is sufficient to distinguish between fixed or dual topology of SMR members and, probably, similar types of membrane proteins. The positive-inside rule can be used to predict the orientation of members in pairs, but is not suitable as a sole predictor of dual topology.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1089-8638
pubmed:author
pubmed:copyrightInfo
Copyright 2010 Elsevier Ltd. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
10
pubmed:volume
402
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
127-38
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Orientation of small multidrug resistance transporter subunits in the membrane: correlation with the positive-inside rule.
pubmed:affiliation
Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't