Proteins induced by anaerobiosis in Escherichia coli

Abstract

The contribution of protein induction and repression to the adaptation of cells to changes in O2 supply is only poorly understood. This contribution was assessed by measuring the levels of 170 individual polypeptides produced by E. coli K-12 in cells growing aerobically or anaerobically with and without nitrate. Eighteen reached their highest levels during anaerobic growth. These 18 polypeptides include at least 4 glycolytic enzymes and pyruvate formate-lyase (.beta.-subunit). Most of these proteins were found at significant levels during aerobic growth and appeared to undergo metabolic regulation by stimuli other than anaerobiosis. Anaerobic induction ratios ranged from 1.8-11-fold and nitrate antagonized the anaerobic induction of all of the proteins except one. The time course of synthesis of the proteins after shifts in O2 supply revealed at least 3 distinct temporal patterns. These results are discussed in light of known physiological alterations associated with changes in O2 availability.