Premium
DNA methylation by CcrM activates the transcription of two genes required for the division of C aulobacter crescentus
Author(s) -
Gonzalez Diego,
Collier Justine
Publication year - 2013
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12180
Subject(s) - ftsz , biology , caulobacter crescentus , gene , dna methylation , promoter , transcription (linguistics) , genetics , dna , cell division , microbiology and biotechnology , gene expression , cell , cell cycle , linguistics , philosophy , escherichia coli
Summary DNA methylation regulates many processes, including gene expression, by superimposing secondary information on DNA sequences. The conserved CcrM enzyme, which methylates adenines in GANTC sequences, is essential to the viability of several A lphaproteobacteria . In this study, we find that C aulobacter crescentus cells lacking the CcrM enzyme accumulate low levels of the two conserved FtsZ and MipZ proteins, leading to a severe defect in cell division. This defect can be compensated by the expression of the ftsZ gene from an inducible promoter or by spontaneous suppressor mutations that promote FtsZ accumulation. We show that CcrM promotes the transcription of the ftsZ and mipZ genes and that the ftsZ and mipZ promoter regions contain a conserved CGACTC motif that is critical to their activities and to their regulation by CcrM . In addition, our results suggest that the ftsZ promoter has the lowest activity when the CGACTC motif is non‐methylated, an intermediate activity when it is hemi‐methylated and the highest activity when it is fully methylated. The regulation of ftsZ expression by DNA methylation may explain why CcrM is essential in a subset of A lphaproteobacteria .