GCA_000020025.1 Npun_R0999 definition cobaltochelatase, CobN subunit GCA_000020025.1 Npun_F1231 definition magnesium and cobalt transport protein CorA GCA_000020025.1 Npun_R1701 definition cobalt transport protein GCA_000020025.1 Npun_F6158 definition cobalt transport protein