Structural highlights
Function[MER_METTM] Catalyzes the reversible reduction of methylene-H(4)MPT to methyl-H(4)MPT. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCoenzyme 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. Structure of coenzyme F(420) dependent methylenetetrahydromethanopterin reductase from two methanogenic archaea.,Shima S, Warkentin E, Grabarse W, Sordel M, Wicke M, Thauer RK, Ermler U J Mol Biol. 2000 Jul 21;300(4):935-50. PMID:10891279[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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