Linked Life Data

2191080

Source:http://linkedlifedata.com/resource/pubmed/id/2191080

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-7-13
pubmed:abstractText
Albicidin blocked DNA synthesis in intact cells of a PolA- EndA- Escherichia coli strain, and in permeabilized cells supplied with all necessary precursor nucleotides, indicating a direct effect on prokaryote DNA replication. Replication of phages T4 and T7 was also blocked by albicidin in albicidin-sensitive (Albs) but not in albicidin-resistant (Albr) E. coli host-cells. All stable spontaneous Albr mutants of E. coli simultaneously became resistant to phage T6. The locus determining albicidin sensitivity mapped at tsx, the structural gene for an outer-membrane protein used as a receptor by phage T6 and involved in transport through the outer membrane of nucleosides present at submicromolar extracellular concentrations. Albicidin does not closely resemble a nucleoside in structure. However, Albs E. coli strains rapidly accumulated both nucleosides and albicidin from the surrounding medium whereas the Albr mutants were defective in uptake of nucleosides and albicidin at low extracellular concentrations. An insertion mutation blocking Tsx protein production also blocked albicidin uptake and conveyed albicidin resistance. Albicidin supplied at approximately 0.1 microM blocked DNA replication within seconds in intact Albs E. coli cells, but a 100-fold higher albicidin concentration was necessary for a rapid inhibition of DNA replication in permeabilized cells. We conclude that albicidin is effective at very low concentrations against E. coli because it is rapidly concentrated within cells by illicit transport through the tsx-encoded outer-membrane channel normally involved in nucleoside uptake. Albicidin resistance results from loss of the mechanism of albicidin transport through the outer membrane.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-1287
pubmed:author
pubmed:issnType
Print
pubmed:volume
136
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
51-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Stable albicidin resistance in Escherichia coli involves an altered outer-membrane nucleoside uptake system.
pubmed:affiliation
Department of Botany, University of Queensland, St Lucia, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't