Linked Life Data

10931356

Source:http://linkedlifedata.com/resource/pubmed/id/10931356

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-9-12
pubmed:abstractText
In wild-type Escherichia coli cells, initiation of DNA replication is tightly coupled to cell growth. In slowly growing dnaA204 (Ts) mutant cells, the cell mass at initiation and its variability is increased two- to threefold relative to wild type. Here, we show that the DnaA protein concentration was two- to threefold lower in the dnaA204 mutant compared with the wild-type strain. The reason for the DnaA protein deficiency was found to be a rapid degradation of the mutant protein. Absence of SeqA protein stabilized the DnaA204 protein, increased the DnaA protein concentration and normalized the initiation mass in the dnaA204 mutant cells. During rapid growth, the dnaA204 mutant displayed cell cycle parameters similar to wild-type cells as well as a normal DnaA protein concentration, even though the DnaA204 protein was highly unstable. Apparently, the increased DnaA protein synthesis compensated for the protein degradation under these growth conditions, in which the doubling time was of the same order of magnitude as the half-life of the protein. Our results suggest that the DnaA204 protein has essentially wild-type activity at permissive temperature but, as a result of instability, the protein is present at lower concentration under certain growth conditions. The basis for the stabilization in the absence of SeqA is not known. We suggest that the formation of stable DnaA-DNA complexes is enhanced in the absence of SeqA, thereby protecting the DnaA protein from degradation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
629-38
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
The Escherichia coli SeqA protein destabilizes mutant DnaA204 protein.
pubmed:affiliation
Departments of Cell Biology, Institute for Cancer Research, Montebello, 0310 Oslo, Norway.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't