Linked Life Data

11260478

Source:http://linkedlifedata.com/resource/pubmed/id/11260478

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-3-22
pubmed:abstractText
The first flagellar assembly checkpoint of Caulobacter crescentus couples assembly of the early class II components of the basal body complex to the expression of class III and IV genes, which encode extracytoplasmic structures of the flagellum. The transcription of class III/IV flagellar genes is activated by the response regulator factor, FlbD. Gain of function mutations in flbD, termed bfa, can bypass the transcriptional requirement for the assembly of class II flagellar structures. Here we show that the class II flagellar gene fliX encodes a trans-acting factor that couples flagellar assembly to FlbD-dependent transcription. We show that the overexpression of fliX can suppress class III/IV gene expression in both wild-type and flbD-bfa cells. Introduction of a bfa allele of flbD into cells possessing a deletion in fliX restores motility indicating that FliX is not a structural component of the flagellum, but rather a trans-acting factor. Furthermore, extragenic motile suppressors which arise in DeltafliX cells map to the flbD locus. These results indicate that FlbD functions downstream of FliX in activating class III/IV transcription. beta-Lactamase fusions to FliX and analysis of cellular fractions demonstrate that FliX is a cytosolic protein that demonstrates some peripheral association with the cytoplasmic membrane. In addition, we have isolated a mutant allele of fliX that exhibits a bfa-like phenotype, restoring flbD-dependent class III/IV transcription in strains that contain mutations in class II flagellar structural genes. Taken together, these results indicated both a positive and negative regulatory function for FliX in coupling the assembly of class II basal body components to gene expression.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1623-37
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
The Caulobacter crescentus flagellar gene, fliX, encodes a novel trans-acting factor that couples flagellar assembly to transcription.
pubmed:affiliation
Department of Chemistry and Biochemistry and the, Molecular Biology Institute, University of California, Los Angeles, CA 90095-1569, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.