Portal de Periódicos da CAPES

The Escherichia coli regulatory protein OxyR discriminates between methylated and unmethylated states of the phage Mu mom promoter.

1989; Springer Nature; Volume: 8; Issue: 8 Linguagem: Inglês

10.1002/j.1460-2075.1989.tb08370.x

1460-2075

Michael Bölker, Regine Kahmann,

Bacteriophages and microbial interactions

Research Article1 August 1989free access The Escherichia coli regulatory protein OxyR discriminates between methylated and unmethylated states of the phage Mu mom promoter. M. Bölker M. Bölker Institut für Genbiologische Forschung Berlin GmbH, FRG. Search for more papers by this author R. Kahmann R. Kahmann Institut für Genbiologische Forschung Berlin GmbH, FRG. Search for more papers by this author M. Bölker M. Bölker Institut für Genbiologische Forschung Berlin GmbH, FRG. Search for more papers by this author R. Kahmann R. Kahmann Institut für Genbiologische Forschung Berlin GmbH, FRG. Search for more papers by this author Author Information M. Bölker1 and R. Kahmann1 1Institut für Genbiologische Forschung Berlin GmbH, FRG. The EMBO Journal (1989)8:2403-2410https://doi.org/10.1002/j.1460-2075.1989.tb08370.x PDFDownload PDF of article text and main figures. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info Expression of the phage Mu mom gene is transcriptionally regulated by DNA methylation. Three GATC sites upstream of the mom promoter have to be methylated by the Escherichia coli deoxyadenosine methylase (Dam) to allow initiation of transcription. An E. coli dam strain was mutagenized with Tn5 in an attempt to isolate mutants which allow mom gene expression. Three independent Tn5 mutants were isolated, each mapped to a gene at 89.6 min which we designate momR. The wildtype gene was cloned and sequenced, it encodes a protein of 305 amino acids. The protein belongs to a group of related bacterial activators recently identified as the LysR family (Henikoff et al., 1988). MomR protein was overproduced and purified. Expression of momR is autoregulated; MomR binds to a 43 bp region upstream of its coding sequence. In the mom promoter MomR protects a 43 bp region containing the three GATC sites. Specific binding to these sequences was observed only with unmethylated DNA. Fortuitously, we learned that MomR is identical to OxyR, a regulatory protein responding to oxidative stress. We discuss the implications of this control for Mu development. Previous ArticleNext Article Volume 8Issue 81 August 1989In this issue RelatedDetailsLoading ...