Structure of coenzyme F(420) dependent methylenetetrahydromethanopterin reductase from two methanogenic archaea.Shima, S., Warkentin, E., Grabarse, W., Sordel, M., Wicke, M., Thauer, R.K., Ermler, U.
(2000) J.Mol.Biol. 300: 935-950
- PubMed: 10891279
- DOI: 10.1006/jmbi.2000.3909
- Primary Citation of Related Structures:
- PubMed Abstract:
Coenzyme F(420)-dependent methylenetetrahydromethanopterin reductase (Mer) is an enzyme of the Cl metabolism in methanogenic and sulfate reducing archaea. It is composed of identical 35-40 kDa subunits and lacks a prosthetic group. The crystal struct ...
Coenzyme F(420)-dependent methylenetetrahydromethanopterin reductase (Mer) is an enzyme of the Cl metabolism in methanogenic and sulfate reducing archaea. It is composed of identical 35-40 kDa subunits and lacks a prosthetic group. The crystal structure of Mer from Methanopyrus kandleri (kMer) revealed in one crystal form a dimeric and in another a tetrameric oligomerisation state and that from Methanobacterium thermoautotrophicum (tMer) a dimeric state. Each monomer is primarily composed of a TIM-barrel fold enlarged by three insertion regions. Insertion regions 1 and 2 contribute to intersubunit interactions. Insertion regions 2 and 3 together with the C-terminal end of the TIM-barrel core form a cleft where the binding sites of coenzyme F(420) and methylene-tetrahydromethanopterin are postulated. Close to the coenzyme F(420)-binding site lies a rarely observed non-prolyl cis-peptide bond. It is surprising that Mer is structurally most similar to a bacterial FMN-dependent luciferase which contains a non-prolyl cis-peptide bond at the equivalent position. The structure of Mer is also related to that of NADP-dependent FAD-harbouring methylenetetrahydrofolate reductase (MetF). However, Mer and MetF do not show sequence similarities although they bind related substrates and catalyze an analogous reaction.
Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch Strasse, Marburg, 35043, Germany.