A Multienzyme Complex Channels Substrates and Electrons through Acetyl-CoA and Methane Biosynthesis Pathways in Methanosarcina

作者：Lieber Dillon J; Catlett Jennifer; Madayiputhiya Nandu; Nandakumar Renu; Lopez Madeline M; Metcalf William W; Buan Nicole R^*

来源：PLos One, 2014, 9(9): e107563.

DOI：10.1371/journal.pone.0107563

Multienzyme complexes catalyze important metabolic reactions in many organisms, but little is known about the complexes involved in biological methane production (methanogenesis). A crosslinking-mass spectrometry (XL-MS) strategy was employed to identify proteins associated with coenzyme M-coenzyme B heterodisulfide reductase (Hdr), an essential enzyme in all methane-producing archaea (methanogens). In Methanosarcina acetivorans, Hdr forms a multienzyme complex with acetyl-CoA decarbonylase synthase (ACDS), and F-420-dependent methylene-H4MPT reductase (Mer). ACDS is essential for production of acetyl-CoA during growth on methanol, or for methanogenesis from acetate, whereas Mer is essential for methanogenesis from all substrates. Existence of a Hdr: ACDS: Mer complex is consistent with growth phenotypes of ACDS and Mer mutant strains in which the complex samples the redox status of electron carriers and directs carbon flux to acetyl-CoA or methanogenesis. We propose the Hdr: ACDS: Mer complex comprises a special class of multienzyme redox complex which functions as a "biological router'' that physically links methanogenesis and acetyl-CoA biosynthesis pathways.

• 出版日期2014-9-18