Piezo-adapted 3-Isopropylmalate dehydrogenase of the obligate piezophile Shewanella benthica DB21MT-2 isolated from the 11,000-m depth of the mariana trench

Abstract

3-Isopropylmalate dehydrogenase (IPMDH)-encoding leuB genes were obtained from the obligate piezophile Shewanella benthica DB21MT-2 and non-piezophile Shewanella oneidensis MR-1. The genes were expressed in Escherichia coli and the proteins were purified using His-tag. The estimated kinetic parameters of these enzymes indicated that IPMDH of S. benthica DB21MT-2 is more tolerant of high pressure than that of S. oneidensis MR-1. Thus such an adaptation is one of the mechanisms bacteria utilize for survival at high pressures.