Linked Life Data

15306019

Source:http://linkedlifedata.com/resource/pubmed/id/15306019

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-8-12
pubmed:abstractText
PcsB is a protein of unknown function(s) that influences the cell morphology of several pathogenic species of streptococcus. PcsB contains a CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) domain found in bacterial murein hydrolases; however, direct links between steps in cell wall biosynthesis and PcsB function(s) have not been demonstrated. We show here that pcsB is essential in the human respiratory pathogen, Streptococcus pneumoniae, that depletion of PcsB is bacteriostatic and that alanine substitutions in the conserved cysteine and histidine residues of the CHAP domain appear to be lethal. We stained wild-type parent and mutant bacteria deficient in expression of PcsB with fluorescent vancomycin and DAPI to determine patterns of cell wall synthesis and nucleoid segregation respectively. The wild-type parent strain exhibited ordered, simultaneous septal and equatorial cell wall synthesis. In contrast, reduced expression of PcsB resulted in formation of long chains of cells in which peptidoglycan synthesis occurred at nearly every division septum and cell equator. Severe depletion of PcsB led to abnormal, uncontrolled cell wall synthesis at misplaced septa and around large cells. Together, these physiological properties are consistent with a role for PcsB as a murein hydrolase that balances the extent of cell wall synthesis in S. pneumoniae. Finally, we show that the defects in morphology and cell wall synthesis that result from depletion of PcsB strongly resemble those caused by depletion of the essential VicRK two component regulatory system (TCS). This result and the essentiality of pcsB support the hypothesis that the essentiality of the VicRK TCS results from its positive regulation of PcsB expression.
pubmed:grant
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
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1161-75
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Defective cell wall synthesis in Streptococcus pneumoniae R6 depleted for the essential PcsB putative murein hydrolase or the VicR (YycF) response regulator.
pubmed:affiliation
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't