Functional interactions between posttranslationally modified amino acids of methyl-coenzyme M reductase in Methanosarcina acetivorans
Fig 1
Crystal structure of MCR from M. acetivorans.
(A) The α2β2γ2 configuration of the inactive MCR complex affinity-purified from M. acetivorans under aerobic conditions. The location of posttranslational modifications, the F430 cofactor, as well as CoM-SH and CoB-SH are highlighted. No electron density corresponding to the affinity tag was observed. (B) A close-up of the active site within the McrA subunit in M. acetivorans. The red shading of the MeHis label indicates that this residue is from the other α-subunit, illustrating the fact that residues from both α-subunits are present in each active site. CoB, methyl-coenzyme B; CoM, methyl-coenzyme M; Dya, Didehydroasparate F430, factor 430; MCR, methyl-coenzyme M reductase; McrA, alpha subunit of MCR; MeArg, 5-(S)-methylarginine; MeCys, S-methylcysteine; MeHis, N1-methylhistidine; ThioGly, thioglycine.