Linked Life Data

1809832

Source:http://linkedlifedata.com/resource/pubmed/id/1809832

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1992-5-27
pubmed:abstractText
Escherichia coli TonB protein is required for the active transport of vitamin B12 and Fe(III)-siderophore complexes across the outer membrane, infection by bacteriophages T1 and phi 80, and sensitivity to B-group colicins. TonB appears to function as an energy transducer in these processes, coupling cytoplasmic membrane electrochemical potential to receptors in the outer membrane. Previous reports have demonstrated that chromosomally encoded TonB is functionally unstable in the absence of protein synthesis (half-life approximately 15-30 minutes) and have shown that plasmid-encoded, overexpressed TonB is chemically unstable (half-life approximately 5 minutes). In contrast, this study has shown that chromosomally encoded TonB was chemically stable for greater than 90 minutes while maintaining its functional instability. These data suggest that proteolytic degradation of TonB protein is not the basis of its functional instability. Auxiliary proteins such as ExbB also play a role in TonB-dependent energy transduction. In this study, we have shown that the chemical half-life of chromosomally encoded TonB in an exbB::Tn10 mutant was reduced at least 18-fold, suggesting that TonB is a part of a cytoplasmic membrane complex that includes, at the minimum, ExbB.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2883-90
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Evidence for a TonB-dependent energy transduction complex in Escherichia coli.
pubmed:affiliation
Department of Microbiology, Washington State University, Pullman 99164-4233.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.