Linked Life Data

9484884

Source:http://linkedlifedata.com/resource/pubmed/id/9484884

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-3-31
pubmed:databankReference
pubmed:abstractText
Conjugal transfer of Agrobacterium tumefaciens Ti plasmids is regulated by two hierarchical signalling systems. Transfer is dependent on a subset of opines produced by the plant tumours induced by the bacterium. Induction also requires an acyl-homoserine lactone signal, called AAI, that is produced by the bacteria themselves. AAI is the co-inducer for TraR, the transcriptional activator required for expression of the tra regulon. Octopine induces conjugation of the octopine-mannityl opine-type Ti plasmids by regulating the expression of traR via OccR, the octopine-dependent activator of the opine regulon. We have discovered a second traR-like gene, trlR, on the octopine-mannityl opine-type Ti plasmids pTi15955 and pTiR10. This gene is located in an operon coding for a mannopine transport system and is expressed as part of the mannityl opine regulon. Sequence analysis indicated that trlR is a frameshift allele of traR, and the resulting protein lacks the carboxy-terminal domain thought to constitute the DNA-binding region of TraR. Expression of trlR inhibited octopine-induced conjugation of pTi15955 and pTiR10 by suppressing the TraR-mediated transcription of the tra and trb operons. Although TrlR had no effect on the expression of traR, TraR activated the expression of trlR. Southern hybridizations indicated that several other Ti and opine-catabolic plasmids contain more than one copy of genes homologous to traR. We propose that trlR is a dominant negative allele of traR and that TrlR inhibits conjugation by forming inactive heteromultimers with TraR.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
277-88
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Octopine-type Ti plasmids code for a mannopine-inducible dominant-negative allele of traR, the quorum-sensing activator that regulates Ti plasmid conjugal transfer.
pubmed:affiliation
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana 61801, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.