Linked Life Data

1730719

Source:http://linkedlifedata.com/resource/pubmed/id/1730719

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-2-18
pubmed:abstractText
The minimum structural information necessary to formulate and assess mechanistic models of integral membrane protein function is that of membrane topology. This paper characterizes the topological structure of the melibiose carrier of Escherichia coli based on constraints provided by genetic fusions to the compartment-specific reporter protein alkaline phosphatase. Twenty-eight unique chimeras exhibiting either low alkaline phosphatase activity (cytoplasmic location of the fusion joint) or high alkaline phosphatase activity (periplasmic location of the fusion joint) were characterized and used in conjunction with Goldman-Engelman-Steitz hydropathy analysis to model topological structure. The melibiose carrier is predicted to have a cytoplasmic amino terminus, two sets of six transmembrane domains separated by an unusually large cytoplasmic loop ("six-loop-six" arrangement), and a 45-residue cytoplasmic carboxyl tail. Remarkably, the identical six-loop-six arrangement is predicted from the hydrophobicity plots of the H(+)-coupled lactose, arabinose, xylose, and citrate cotransporters of E. coli, the glucose transporter from rat brain, the family of glucose transporters isolated from various human tissues and cell lines, and the human, mouse, and hamster multidrug resistance transporters (Henderson, P.J.F. (1990) Res. Microbiol. 141, 316-328; Maloney, P.C. (1990) Res. Microbiol. 141, 374-383). Such a broad degree of conservation (or convergence) suggests a distinct structural and/or mechanistic advantage associated with the six-loop-six motif. The nature of this advantage is as yet unknown.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
267
pubmed:geneSymbol
melB, phoA
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1818-22
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Membrane topology of the melibiose carrier of Escherichia coli.
pubmed:affiliation
Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, Massachusetts 02115.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.