Open AccessMethylation dependent expression of themomgene of bacteriophage Mu: deletions downstream from the methylation sites affect expression
Author(s) -
Catherine C. Adley,
Ahmad I. Bukhari
Publication year - 1984
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/12.8.3535
Subject(s) - biology , methylation , dna methylation , genetics , gene , microbiology and biotechnology , transcription (linguistics) , promoter , gene expression , transactivation , start codon , epigenetics of physical exercise , regulation of gene expression , nucleotide , linguistics , philosophy
The expression of the DNA modification gene (mom) of bacteriophage Mu requires the cellular deoxyadenosine methylase (dam) and a transactivation factor from the phage. By hypothesis, the transcription of mom is activated by methylation of three GATC sequences upstream from the mom gene. We have introduced small deletions at a fourth GATC site located about 140 base pairs downstream from the primary methylation region. Some of the deletions severely affect the mom gene expression. We propose from this analysis that (1) some important elements, possibly the promoter, concerned with the expression of mom are located between nucleotides 840 and 880 from the right end of Mu and (2) the mom protein starts with the codon GTG located at position 810. We favor the hypothesis that methylation turns off transcription upstream, thereby allowing the main mom promoter to function.