ID 4.99.1.3 DE sirohydrochlorin cobaltochelatase. AN anaerobic cobalt chelatase. AN cobaltochelatase. CA (1) Co-sirohydrochlorin + 2 H(+) = Co(2+) + sirohydrochlorin. CA (2) Co-precorrin-2 + 3 H(+) = Co(2+) + precorrin-2. CC -!- This enzyme, which forms part of the anaerobic (early cobalt CC insertion) cobalamin biosynthesis pathway, is a type II chelatase. CC -!- It is ATP-independent and exists as either a monomer (CbiX) or a CC homodimer (CibK). CC -!- CbiK from Salmonella enterica uses precorrin-2 as the substrate to CC yield cobalt-precorrin-2. CC -!- The enzyme contains two histidines at the active site that are CC thought to be involved in the deprotonation of the tetrapyrrole CC substrate as well as in metal binding. CC -!- CbiX from Bacillus megaterium inserts cobalt at the level of CC sirohydrochlorin (factor-II) rather than precorrin-2. CC -!- See EC 6.6.1.2 for the cobaltochelatase that participates in the CC aerobic cobalamin biosynthesis pathway. DR Q72CB8, CBIKC_DESVH; Q72EC8, CBIKP_DESVH; Q05592, CBIK_SALTY ; DR O29537, CBIX_ARCFU ; Q9HQM3, CBIX_HALSA ; O87690, CBIX_PRIMG ; DR Q980A7, CBIX_SACS2 ; Q4JAI2, CBIX_SULAC ; C3MZ53, CBIX_SULIA ; DR C4KID1, CBIX_SULIK ; C3MR05, CBIX_SULIL ; C3MWZ3, CBIX_SULIM ; DR C3NGG2, CBIX_SULIN ; C3N773, CBIX_SULIY ; Q975N6, CBIX_SULTO ; DR Q55451, CBIX_SYNY3 ; A6UWT5, CFBA_META3 ; Q8TJZ5, CFBA_METAC ; DR P61816, CFBA_METBF ; Q12X56, CFBA_METBU ; Q58380, CFBA_METJA ; DR Q8TY77, CFBA_METKA ; Q8PZH6, CFBA_METMA ; P61819, CFBA_METMP ; DR O27448, CFBA_METTH ; //