Site-specific methylases induce the SOS DNA repair response in Escherichia coli.

AUTOR(ES)

Heitman, J

RESUMO

Expression of the site-specific adenine methylase HhaII (GmeANTC, where me is methyl) or PstI (CTGCmeAG) induced the SOS DNA repair response in Escherichia coli. In contrast, expression of methylases indigenous to E. coli either did not induce SOS (EcoRI [GAmeATTC] or induced SOS to a lesser extent (dam [GmeATC]). Recognition of adenine-methylated DNA required the product of a previously undescribed gene, which we named mrr (methylated adenine recognition and restriction). We suggest that mrr encodes an endonuclease that cleaves DNA containing N6-methyladenine and that DNA double-strand breaks induce the SOS response. Cytosine methylases foreign to E. coli (MspI [meCCGG], HaeIII [GGmeCC], BamHI [GGATmeCC], HhaI [GmeCGC], BsuRI [GGmeCC], and M.Spr) also induced SOS, whereas one indigenous to E. coli (EcoRII [CmeCA/TGG]) did not. SOS induction by cytosine methylation required the rglB locus, which encodes an endonuclease that cleaves DNA containing 5-hydroxymethyl- or 5-methylcytosine (E. A. Raleigh and G. Wilson, Proc. Natl. Acad. Sci. USA 83:9070-9074, 1986).

Documentos Relacionados

• SOS induction and autoregulation of the himA gene for site-specific recombination in Escherichia coli.
• Site-specific mutagenesis of histidine residues in the lac permease of Escherichia coli.
• Expression and site-specific mutagenesis of the poliovirus 3C protease in Escherichia coli.
• Mutations in uvrD induce the SOS response in Escherichia coli.
• Rapid site-specific DNA inversion in Escherichia coli mutants lacking the histonelike protein H-NS.