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Titolo:
Loss-of-function mutations in yjbD result in ClpX- and CipP-independent competence development of Bacillus subtilis
Autore:
Nakano, MM; Hajarizadeh, F; Zhu, Y; Zuber, P;
Indirizzi:
Oregon Hlth & Sci Univ, OGI Sch Sci & Engn, Dept Biochem & Mol Biol, Beaverton, OR 97006 USA Oregon Hlth & Sci Univ Beaverton OR USA 97006 ol, Beaverton, OR 97006 USA
Titolo Testata:
MOLECULAR MICROBIOLOGY
fascicolo: 2, volume: 42, anno: 2001,
pagine: 383 - 394
SICI:
0950-382X(200110)42:2<383:LMIYRI>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
DEGRADATIVE ENZYME-SYNTHESIS; COMPLETE GENOME SEQUENCE; GENETIC COMPETENCE; TRANSCRIPTION FACTOR; SIGNAL-TRANSDUCTION; ESCHERICHIA-COLI; NUTRITIONAL REPRESSION; REGULATORY PROTEIN; SPORULATION; SRFA;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
71
Recensione:
Indirizzi per estratti:
Indirizzo: Zuber, P Oregon Hlth & Sci Univ, OGI Sch Sci & Engn, Dept Biochem & Mol Biol, Beaverton, OR 97006 USA Oregon Hlth & Sci Univ Beaverton OR USA 97006 rton, OR 97006 USA
Citazione:
M.M. Nakano et al., "Loss-of-function mutations in yjbD result in ClpX- and CipP-independent competence development of Bacillus subtilis", MOL MICROB, 42(2), 2001, pp. 383-394

Abstract

Mutations in clpP and clpX have pleiotropic effects on growth and developmentally regulated gene expression in Bacillus subtilis. ClpP and ClpX are needed for expression of comK, encoding the competence transcription factor required for the expression of genes within the competence regulon. ClpP, in combination with the ATPase ClpC, degrades the inhibitor of ComK, MecA. Proteolysis of MecA is stimulated by a small protein, ComS, which interacts with MecA. Suppressor mutations (cxs) were isolated that bypass the requirement for clpX for comK expression. These were found also to overcome the defect in comK expression conferred by a clpP mutation. These mutations were identified as missense mutations (cxs-5, -7 and -12) and a nonsense (UAG) codon substitution (cxs-10) in the yjbD coding sequence in a locus linked tomecA. That a yjbD disruption confers the cxs phenotype, together with its complementation by an ectopically expressed copy of yjbD, indicated that the suppressor alleles bear recessive, loss-of-function mutations of yjbD. ClpP- and ClpX-independent comK expression rendered by inactivation of yjbD was still medium-dependent and required ComS. MecA levels in a clpP-yjbD mutant were lower that those of clpP mutant cells and ComK protein concentration in the clpP mutant was restored to wild-type levels by the yjbD mutation. Consequently, the yjbD mutation bypasses the defect in competence development conferred by clpP and clpX. YjbD protein is barely detectable in wildtype cells, but is present in large amounts in the clpP mutant cells. The results suggest that the role of ClpP in competence development is to degradeYjbD protein so that ComS can productively interact with the MecA-ClpC-ComK complex. Alternatively, the result could suggest that YjbD has a negativeeffect on regulated proteolysis and that MecA is degraded independently ofClpP when YjbD is absent.

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Documento generato il 23/11/20 alle ore 19:39:33