Escherichia coli OxyR modulation of bacteriophage Mu mom expression in dam+ cells can be attributed to its ability to bind hemimethylated Pmom promoter DNA.
Transcription of the bacteriophage Mu mom operon is strongly repressed by the host OxyR protein in dam - but not dam + cells. In this work we show that the extent of mom modification is sensitive to the relative levels of the Dam and OxyR proteins and OxyR appears to modulate the level of mom expression even in dam + cells. In vitro studies demonstrated that OxyR is capable of binding hemimethylated P mom , although its affinity is reduced slightly compared with unmethylated DNA. Thus, OxyR modulation of mom expression in dam + cells can be attributed to its ability to bind hemimethylated P mom DNA, the product of DNA replication.
Hattman
S
S
Department of Biology, University of Rochester, Rochester, NY 14627, USA.
Sun
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W
D010583:Bacteriophage mu / Q000235:genetics*; D019175:DNA Methylation; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000821:virology; D029968:Escherichia coli Proteins; D015967:Gene Expression Regulation, Viral / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C499299:oxyR protein, E coli; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); C499294:dam protein, E coli