TY - JOUR
T1 - The roles of hydrogenases 3 and 4, and the F0F1-ATPase, in H2 production by Escherichia coli at alkaline and acidic pH
AU - Bagramyan, Karine
AU - Mnatsakanyan, Nelli
AU - Poladian, Anna
AU - Vassilian, Anait
AU - Trchounian, Armen
N1 - Funding Information:
We thank Professors A. Bock, M. Berlyn and W. Epstein for the supply of strains. Many thanks to Drs. S.C. Andrews and P. Golby, and Y. Chang and D. Skibinski for the help in some measurements, advice and comments. Special thanks to S.C. Andrews who did his best to improve the manuscript. The studies at Yerevan State University were supported by a grant from the Ministry of Education and Science of Armenia. The study at the University of Reading was supported by the Royal Society.
PY - 2002/4/10
Y1 - 2002/4/10
N2 - The hyc operon of Escherichia coli encodes the H2-evolving hydrogenase 3 (Hyd-3) complex that, in conjunction with formate dehydrogenase H (Fdh-H), constitutes a membrane-associated formate hydrogenlyase (FHL) catalyzing the disproportionation of formate to CO2 and H2 during fermentative growth at low pH. Recently, an operon (hyf) encoding a potential second H2-evolving hydrogenase (Hyd-4) was identified in E. coli. In this study the roles of the hyc- and hyf-encoded systems in formate-dependent H2 production and Fdh-H activity have been investigated. In cells grown on glucose under fermentative conditions at slightly acidic pH the production of H2 was mostly Hyd-3- and Fdh-H-dependent, and Fdh-H activity was also mainly Hyd-3-dependent. However, at slightly alkaline pH, H2 production was found to be largely Hyd-4, Fdh-H and F0F1-ATPase-dependent, and Fdh-H activity was partially dependent on Hyd-4 and F0F1-ATPase. These results suggest that, at slightly alkaline pH, H2 production and Fdh-H activity are dependent on both the F0F1-ATPase and a novel FHL, designated FHL-2, which is composed of Hyd-4 and Fdh-H, and is driven by a proton gradient established by the F0F1-ATPase.
AB - The hyc operon of Escherichia coli encodes the H2-evolving hydrogenase 3 (Hyd-3) complex that, in conjunction with formate dehydrogenase H (Fdh-H), constitutes a membrane-associated formate hydrogenlyase (FHL) catalyzing the disproportionation of formate to CO2 and H2 during fermentative growth at low pH. Recently, an operon (hyf) encoding a potential second H2-evolving hydrogenase (Hyd-4) was identified in E. coli. In this study the roles of the hyc- and hyf-encoded systems in formate-dependent H2 production and Fdh-H activity have been investigated. In cells grown on glucose under fermentative conditions at slightly acidic pH the production of H2 was mostly Hyd-3- and Fdh-H-dependent, and Fdh-H activity was also mainly Hyd-3-dependent. However, at slightly alkaline pH, H2 production was found to be largely Hyd-4, Fdh-H and F0F1-ATPase-dependent, and Fdh-H activity was partially dependent on Hyd-4 and F0F1-ATPase. These results suggest that, at slightly alkaline pH, H2 production and Fdh-H activity are dependent on both the F0F1-ATPase and a novel FHL, designated FHL-2, which is composed of Hyd-4 and Fdh-H, and is driven by a proton gradient established by the F0F1-ATPase.
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U2 - 10.1016/S0014-5793(02)02555-3
DO - 10.1016/S0014-5793(02)02555-3
M3 - Article
C2 - 11959127
AN - SCOPUS:0037051994
SN - 0014-5793
VL - 516
SP - 172
EP - 178
JO - FEBS Letters
JF - FEBS Letters
IS - 1-3
ER -