Linked Life Data

11298275

Source:http://linkedlifedata.com/resource/pubmed/id/11298275

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-4-12
pubmed:abstractText
In Bacillus subtilis, competence for transformation develops in 5-10% of the cells in a stationary phase culture. These cells exhibit a prolonged lag in the resumption of growth and cell division during the escape from competence. To better understand the basis of this lag, we have characterized competent cultures microscopically. To distinguish the minority of competent cells, a translational fusion between ComK, the competence transcription factor, and the green fluorescent protein (GFP) was used as a marker. Only 5-10% of the cells in a competent culture were fluorescent, indicating that ComK synthesis is an all or nothing event. To validate the identification of competent cells, we demonstrated the coincident expression of comEA, a late competence gene, and comK-gfp. Competent cells resemble stationary phase cells; the majority are single (not in chains), contain single nucleoids, and rarely contain FtsZ rings. Upon dilution into fresh medium, competent cells maintain this appearance for about 2 h. In contrast, the majority of non-competent cells rapidly resume growth, exhibiting chaining, nuclear division and FtsZ-ring formation. The late competence protein ComGA is required for the competence-related block in chromosome replication and cell division. In the competent cells of a comGA mutant culture, chromosomal replication and FtsZ-ring formation were no longer blocked, although competent comGA mutant cells were abnormal in appearance. It is likely that one role for ComGA is to prevent growth, chromosome replication and cell division until ComK can be eliminated by degradation. A mutation in the ATP-binding site of comGA inactivated the protein for transformation but did not prevent it from inhibiting DNA replication and cell division. The buoyant density difference between competent and non-competent cells depends on the competence-specific growth arrest.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
52-64
pubmed:dateRevised
2011-8-12
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
A ComGA-dependent checkpoint limits growth during the escape from competence.
pubmed:affiliation
Public Health Research Institute, 455 First Ave, New York, NY 10016, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.