Figure 2.

Representative crystal structures of MCRs and ECR. (A) MCR from M. marburgensis and (B) the associated active site with F₄₃₀, HS-CoB, and HS-CoM. (C) Black Sea mat ANME-1 MCR active site with 17²-methylthio-F₄₃₀, HS-CoB, and HS-CoM. (D) Ca. E. thermophilum ECR active site with dimethyl-F₄₃₀, HS-CoB, and HS-CoM. α subunits are shown in marine and deep blue, β subunits in hot pink and violet, γ subunits in forest green, F₄₃₀ in orange, coenzyme M in deep teal, and coenzyme B in lime green.