Analysis of the methylation-regulated Mu mom transcript.
The Mu mom gene is transcribed only when DNA is methylated by Dam; this methylation dependence is determined by a region upstream of the gene containing three Dam-methylation sites. The mom operon contains two open reading frames, one of which codes for Mom. Experiments were done to find a function for the other reading frame; it is shown that it does not affect phage immunity or the regulation of mom expression. Deletion mapping and S1 nuclease mapping experiments identify the +1 of the mom mRNA: it is 45 bp downstream of the three Dam-methylation sites. Possible models for the short-distance transcription regulation by methylation are discussed. The mom promoter is surrounded by sequences that are shown to be homologous to the oriC region of E. coli. This suggests a relation between replication and methylation-dependent mom expression. It is shown however, that replication is not essential for mom expression.
D010583:Bacteriophage mu / Q000235:genetics*; D001483:Base Sequence; D004261:DNA Replication; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D005796:Genes; D005814:Genes, Viral; D008745:Methylation; D009876:Operon; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D014158:Transcription, Genetic
D004279:DNA, Viral; D012333:RNA, Messenger; D012367:RNA, Viral