N5 ,N10 ‐Methylenetetrahydromethanopterin dehydrogenase from Methanobacterium thermoautotrophicum has hydrogenase activity

FEBS Letters

Thauer, R.K.¹  Zirngibl, C.¹  Hedderich, R.¹ 

[1] Laboratorium für Mikrobiologie, Fachbereich Biologie, Philipps-Universität Marburg, Karl-von-Frisch-Straβe, D-3550 Marburg, FRG

关键词: Methanopterin;    Tetrahydromethanopterin;    Methylenetetrahydromethanopterin dehydrogenase;    Hydrogenase;    Coenzyme F420;    Methanobacterium thermoautotrophicum;   

DOI  :  10.1016/0014-5793(90)80649-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

N⁵,N¹⁰-Methylenetetrahydromethanopterin dehydrogenase from Methanobacterium thermoautotrophicum (strain Marburg) was purified under anaerobic conditions to apparent homogeneity and a specific activity of approximately 750 μol/min/mg protein. Polyacrylamide gel electrophoresis under native and denaturing conditions revealed that the enzyme is composed of only one polypeptide with an apparent molecular mass of 43 kDa. The purified enzyme catalyzed the dehydrogenation of N⁵,N¹⁰-methylenetetrahydromethanopterin (CH₂=H₄MPT) (apparent K_m≡20 μM) to N⁵,N¹⁰-methenyltetrahydromethanopterin (CH≡H₄MPT) in the absence of any added electron acceptors. One mol of H₂ was generated per mol CH≡H₄MPT formed, indicating that protons served as electron acceptor. Coenzyme F₄₂₀, NAD, NADP and viologen dyes were not reduced by CH₂=H₄MPT. The dehydrogenase also catalyzed the reverse reaction, the reduction of CH≡H₄MPT to CH₂=H₄MPT with H₂. The data indicate that CH₂=H₄MPT dehydrogenase from M. thermoautotrophicum is a novel type of hydrogenase.

【 授权许可】

Unknown