Biochemistry of Methyl-Coenzyme M Reductase: The Nickel Metalloenzyme that Catalyzes the Final Step in Synthesis and the First Step in Anaerobic Oxidation of the Greenhouse Gas Methane - The Metal-Driven Biogeochemistry of Gaseous Compounds in the Environment - page 135

Figure 4 Comparison of the two leading proposals for the methyl-coenzyme M reductase catalytic mechanism. Also shown below the mechanisms is the
proposed first transition state for C-S bond cleavage, based on [ 102 ]. See text for details.