Transcriptome analysis of acetyl phosphate-free mutant and its physiological role in Escherichia coli

Abstract

Physiological meanings producing acetate in Eshcherichia coli have been studied for decades of years. It was reported that the accumulation of acetate in the cultivation decrease the cell growth rate and the production of recombinant protein in E. coli. Acetate is produced along with a simple pathway in which acetyl coenzyme A (acetyl-CoA) is converted to acetyl phosphate by phosphotransacetylase (Pta), then to acetate by acetate kinase (Ack) with producing an ATP. One of the important meanings of acetate metabolism pathway is the production of acetyl phosphate, a small molecule phospho-donor, which may be a global signal in E. coli by phosphorylating various signal transduction response regulators. In this study, transcriptome analysis using DNA microarray was performed for comparison the metabolism of E. coli ackA-pta free mutant with that of the wild type E. coli. The physiological states with or without acetyl phosphate in vivo were compared and understood by the analysis of metabolites during the cultures and the complementation analysis of ackA-pta free mutant.