Reconstitution and properties of a coenzyme F420-mediated formate hydrogenlyase system in Methanobacterium formicicum.
Formate hydrogenlyase activity in a cell extract of Methanobacterium formicicum was abolished by removal of coenzyme F420; addition of purified coenzyme F420 restored activity. Formate hydrogenlyase activity was reconstituted with three purified components from M. formicicum: coenzyme F420-reducing hydrogenase, coenzyme F420-reducing formate dehydrogenase, and coenzyme F420. The reconstituted system required added flavin adenine dinucleotide (FAD) for maximal activity. Without FAD, the formate dehydrogenase and hydrogenase rapidly lost coenzyme F420-dependent activity relative to methyl viologen-dependent activity. Immunoadsorption of formate dehydrogenase or coenzyme F420-reducing hydrogenase from the cell extract greatly reduced formate hydrogenlyase activity; addition of the purified enzymes restored activity. The formate hydrogenlyase activity was reversible, since both the cell extract and the reconstituted system produced formate from H2 plus CO2 and HCO3-.
Baron
S F
SF
Department of Anaerobic Microbiology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
Ferry
J G
JG
D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D004795:Enzyme Stability; D019605:Euryarchaeota / Q000201:enzymology* / Q000378:metabolism; D005182:Flavin-Adenine Dinucleotide / Q000502:physiology; D005560:Formate Dehydrogenases / Q000378:metabolism*; D006864:Hydrogenase / Q000378:metabolism*; D007163:Immunosorbent Techniques; D009097:Multienzyme Complexes / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism; D012256:Riboflavin / Q000031:analogs & derivatives* / Q000502:physiology
D009097:Multienzyme Complexes; D005182:Flavin-Adenine Dinucleotide; C015084:coenzyme F420; D010088:Oxidoreductases; D006864:Hydrogenase; C033895:coenzyme F420 hydrogenase; D005560:Formate Dehydrogenases; C054017:formate hydrogenlyase; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase; D012256:Riboflavin