methyltransferase activity cobalt-precorrin-6B C5-methyltransferase activity https://github.com/geneontology/go-ontology/issues/30193 precorrin-6Y methylase cobalt-precorrin 6B C5-methyltransferase activity RHEA:36067 molecular_function MetaCyc:RXN-8766 precorrin-6 methyltransferase activity GO:0043776 precorrin-6Y C5,15-methyltransferase (decarboxylating) Catalysis of the reaction: S-adenosylmethionine + cobalt-precorrin 6B = S-adenosylhomocysteine + cobalt-precorrin 7.