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cAMP‐CRP co‐ordinates the expression of the protein acetylation pathway with central metabolism in Escherichia coli
Author(s) -
CastañoCerezo Sara,
Bernal Vicente,
BlancoCatalá Jorge,
Iborra José L.,
Cánovas Manuel
Publication year - 2011
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/j.1365-2958.2011.07873.x
Subject(s) - biology , catabolite repression , acetylation , acetyltransferase , escherichia coli , biochemistry , regulation of gene expression , mutant , transcription (linguistics) , post translational regulation , lysine , camp receptor protein , psychological repression , gene , gene expression , promoter , amino acid , linguistics , philosophy
Summary Lysine acetylation is a well‐established post‐translational modification widely conserved and distributed in bacteria. Although multiple regulatory roles have been proved, little is known about its regulation. Here, we present evidence that the transcription of the Gcn5‐like acetyltransferase YfiQ of Escherichia coli (proposed name: PatZ) is regulated by cAMP‐CRP and its implications on acetate metabolism regulation. The acetate scavenging acetyl‐CoA synthetase (Acs) is regulated at the transcriptional and post‐translational levels. Post‐translational regulation depends on a protein acetyltransferase ( yfiQ ) and an NAD + ‐dependent deacetylase ( cobB ). We have studied their expression under different environmental conditions. cobB is constitutively expressed from a promoter located upstream nagK . The expression of yfiQ occurs from its own promoter; it is upregulated in the stationary phase and in the presence of non‐PTS carbon sources and is positively regulated by cAMP‐CRP. Two putative CRP binding sites are necessary for its full activity. Gene deletion revealed that cobB is essential for growth on acetate, yfiQ deletion restoring growth of the cobB mutant. The fine tuning of metabolic enzymes results from the integration of multiple mechanisms, and redundant systems may exist. Despite the existence of divergent catabolite repression systems, this may be a conserved strategy common to both Gram‐positive and ‐negative bacteria.