Linked Life Data

11970956

Source:http://linkedlifedata.com/resource/pubmed/id/11970956

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
2002-6-24
pubmed:abstractText
Aminoacyl-tRNA synthetases, a family of enzymes essential for protein synthesis, are promising targets of antimicrobials. Indolmycin, a secondary metabolite of Streptomyces griseus and a selective inhibitor of prokaryotic tryptophanyl-tRNA synthetase (TrpRS), was used to explore the mechanism of inhibition and to explain the resistance of a naturally occurring strain. Streptomyces coelicolor A3(2), an indolmycin-resistant strain, contains two trpS genes encoding distinct TrpRS enzymes. We show that TrpRS1 is indolmycin-resistant in vitro and in vivo, whereas TrpRS2 is sensitive. The lysine (position 9) in the enzyme tryptophan binding site is essential for making TrpRS1 indolmycin-resistant. Replacement of lysine 9 by glutamine, which at this position is conserved in most bacterial TrpRS proteins, abolished the ability of the mutant trpS gene to confer indolmycin resistance in vivo. Molecular modeling suggests that lysine 9 sterically hinders indolmycin binding to the enzyme. Tryptophan recognition (assessed by k(cat)/K(M)) by TrpRS1 is 4-fold lower than that of TrpRS2. Examination of the mRNA for the two enzymes revealed that only TrpRS2 mRNA is constitutively expressed, whereas mRNA for the indolmycin-resistant TrpRS1 enzyme is induced when the cells are exposed to indolmycin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23882-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Indolmycin resistance of Streptomyces coelicolor A3(2) by induced expression of one of its two tryptophanyl-tRNA synthetases.
pubmed:affiliation
RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't