Linked Life Data

7487110

Source:http://linkedlifedata.com/resource/pubmed/id/7487110

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-12-14
pubmed:abstractText
The primary site of action for the novel antibiotic, bicyclomycin, in Escherichia coli has been identified to be the rho transcription termination factor. The inhibition of rho poly(C)-stimulated hydrolysis of ATP by bicyclomycin has been found to proceed by a non-competitive, reversible pathway with respect to ATP (Ki = 20 microM). Inhibition by dihydrobicyclomycin was similar (Ki = 75 microM). No change in the inhibitory properties of the antibiotic was observed under the assay conditions with the two rho mutants, Cys202Gly and Cys202Ser, indicating that Cys-202 does not affect drug binding to rho. Prolonged incubation (32 degrees C, 12 h) of wild-type rho with bicyclomycin (20 mM) led to protein degradation and a slow, permanent loss of rho ATPase activity after dialysis. Evidence was obtained that trace amounts of proteases present with bicyclomycin were responsible for the observed protein degradation. Treatment of wild-type and mutant rho proteins with purified bicyclomycin (25 mM) led to approximately 80% loss of ATPase activity after dialysis with no apparent loss of protein. However, a reduction of the electrophoretic mobility of the bicyclomycin-treated rho versus wild-type rho was seen. Addition of either ATP or poly(C) to wild-type rho led to partial protection against bicyclomycin inactivation, while inclusion of both ligands provided near complete protection against inactivation. The observed loss of ATPase activity upon prolonged incubation of rho with excess purified bicyclomycin is attributed to the covalent modification of the protein by the antibiotic at multiple sites.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
323
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
447-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Bicyclomycin and dihydrobicyclomycin inhibition kinetics of Escherichia coli rho-dependent transcription termination factor ATPase activity.
pubmed:affiliation
Department of Chemistry, University of Houston, Texas 77204, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't