Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
2005-8-1
pubmed:abstractText
ParG is the prototype of a group of small (<10 kDa) proteins involved in accurate plasmid segregation. The protein is a dimeric DNA binding factor, which consists of symmetric paired C-terminal domains that interleave into a ribbon-helix-helix fold that is crucial for the interaction with DNA, and unstructured N-terminal domains of previously unknown function. Here the ParG protein is shown to be a transcriptional repressor of the parFG genes. The protein assembles on its operator site initially as a tetramer (dimer of dimers) and, at elevated protein concentrations, as a pair of tetramers. Progressive deletion of the mobile N-terminal tails concomitantly decreased transcriptional repression by ParG and perturbed the DNA binding kinetics of the protein. The flexible tails are not necessary for ParG dimerization but instead modulate the organization of a higher order nucleoprotein complex that is crucial for proper transcriptional repression. This is achieved by transient associations between the flexible and folded domains in complex with the target DNA. Numerous ParG homologs encoded by plasmids of Gram-negative bacteria similarly are predicted to possess N-terminal disordered tails, suggesting that this is a common feature of partition operon autoregulation. The results provide new insights into the role of natively unfolded domains in protein function, the molecular mechanisms of transcription regulation, and the control of plasmid segregation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
28683-91
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
The unstructured N-terminal tail of ParG modulates assembly of a quaternary nucleoprotein complex in transcription repression.
pubmed:affiliation
Faculty of Life Sciences, The University of Manchester, Manchester M60 1QD, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't