近日，國際著名雜志Nature在線刊登了國外研究人員的最新研究成果“Structure of a methyl-coenzyme M reductase from Black Sea mats that oxidize methane anaerobically。”,，文章中,，作者揭示了一種甲烷氧化酶的晶體結(jié)構(gòu)。
喜甲烷古細菌和硫酸鹽還原細菌中負責甲烷的“厭氧氧化”的酶,，被認為是甲基-輔酶M還原酶（MCR）的一個同源物,，后者催化產(chǎn)甲烷古細菌中的甲烷生成步驟。現(xiàn)在,，研究人員從來自含有ANME-1類古細菌的黑海“藻苔墊”的一個環(huán)境樣本中結(jié)晶出了一種MCR酶,。該結(jié)構(gòu)顯示了輔酶M和輔酶B是怎樣與金屬酶相結(jié)合的，而ANME-1 MCR和產(chǎn)甲烷MCR結(jié)構(gòu)之間的差別可幫助解釋這些同源蛋白不同的酶活性,。（生物谷Bioon.com）
doi:10.1038/nature10663
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Structure of a methyl-coenzyme M reductase from Black Sea mats that oxidize methane anaerobically
Seigo Shima, Martin Krueger, Tobias Weinert, Ulrike Demmer, Jörg Kahnt, Rudolf K. Thauer & Ulrich Ermler
The anaerobic oxidation of methane (AOM) with sulphate, an area currently generating great interest in microbiology, is accomplished by consortia of methanotrophic archaea (ANME) and sulphate-reducing bacteria1, 2. The enzyme activating methane in methanotrophic archaea has tentatively been identified as a homologue of methyl-coenzyme M reductase (MCR) that catalyses the methane-forming step in methanogenic archaea3, 4. Here we report an X-ray structure of the 280 kDa heterohexameric ANME-1 MCR complex. It was crystallized uniquely from a protein ensemble purified from consortia of microorganisms collected with a submersible from a Black Sea mat catalysing AOM with sulphate4. Crystals grown from the heterogeneous sample diffract to 2.1 Å resolution and consist of a single ANME-1 MCR population, demonstrating the strong selective power of crystallization. The structure revealed ANME-1 MCR in complex with coenzyme M and coenzyme B, indicating the same substrates for MCR from methanotrophic and methanogenic archaea. Differences between the highly similar structures of ANME-1 MCR and methanogenic MCR include a F430 modification, a cysteine-rich patch and an altered post-translational amino acid modification pattern, which may tune the enzymes for their functions in different biological contexts.
