Linked Life Data

10985747

Source:http://linkedlifedata.com/resource/pubmed/id/10985747

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2001-2-2
pubmed:abstractText
The O protein is a replication initiator that binds to the orilambda region and promotes assembly of the bacteriophage lambda replication complex. This protein, although protected from proteases by other elements of the replication complex, in a free form is rapidly degraded in the host, Escherichia coli, by the ClpP/ClpX protease. Nevertheless, the physiological role of this rapid degradation remains unclear. Here we demonstrate that the copy number of plasmids derived from bacteriophage lambda is significantly higher in wild-type cells growing in rich media than in slowly growing bacteria. However, lambda plasmid copy number in bacteria devoid of the ClpP/ClpX protease was not dependent on the bacterial growth rate and in all minimal media tested was comparable to that observed in wildtype cells growing in a rich medium. Contrary to lambda plasmid replication, the efficiency of lytic growth of bacteriophage lambda was found to be dependent on the host growth rate in both wild-type bacteria and clpP and clpX mutants. The activities of two major lambda promoters operating during the lytic development, p(R) and p(L), were found to be slightly dependent on the host growth rate. However, when p(R) activity was significantly decreased in the dnaA mutant, production of phage progeny was completely abolished at low growth rates. These results indicate that the O protein (whose level in E. coli cells depends on the activity of ClpP/ClpX protease) is a major limiting factor in the regulation of lambda plasmid replication at low bacterial growth rates. However, this protein seems to be only one of the limiting factors in the bacteriophage lambda lytic development under poor growth conditions of host cells. Therefore, it seems that the role of the rapid ClpP/ClpX-mediated proteolysis of the O protein is to decrease the efficiency of early DNA replication of the phage in slowly growing host cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0302-8933
pubmed:author
pubmed:issnType
Print
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
89-96
pubmed:dateRevised
2009-9-3
pubmed:meshHeading
pubmed:articleTitle
ClpP/ClpX-mediated degradation of the bacteriophage lambda O protein and regulation of lambda phage and lambda plasmid replication.
pubmed:affiliation
Laboratory of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Gda?sk, Poland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't