Si-face stereospecificity at C5 of coenzyme F sub(420) for F sub(420)-dependent N super(5),N super(10)-methylenetetrahydro methanopterin dehydrogenase, F sub(420)-dependent N super(5),N super(10)-methylenetetrahydro methanopterin reductase and F sub(420)H sub(2) dimethylnaphthoquinone oxidoreductase

• Published in: European journal of biochemistry Vol. 214; no. 3; pp. 641 - 646
• Main Authors: Kunow, J, Schwoerer, B, Setzke, E, Thauer, R K
• Format: Journal Article
• Language: English
• Published: 01.01.1993
• ISSN: 0014-2956

Coenzyme F sub(420)-dependent enzymes catalyze the reversible reduction of F sub(420) by stereospecific hydride transfer to C5 of 5-deazaflavin. Two F sub(420)-dependent enzymes have been investigated with respect to the stereochemistry of hydride transfer, the F sub(420)-dependent NADP reductase and the F sub(420)-reducing hydrogenase. Both enzymes were found to be Si-face specific. In this study we report that three additional F sub(420)-dependent enzymes are also Si-face specific: N super(5),N super(10)-methylenetetrahydro-methanopterin dehydrogenase, N super(5),N super(10)-methylenetetrahydro methanopterin reductase and coenzyme F sub(420)H sub(2) dimethylnaphthoquinone oxidoreductase (F sub(420)H sub(2) dehydrogenase). Thus, all five characterized F sub(420)-dependent enzymes are Si-face specific, which is noteworthy since coenzyme F sub(420) is functionally similar to pyridine nucleotides and both Si-face specific and Re-face specific pyridine-nucleotide-dependent enzymes exist.