InterPro : IPR012804

Name  Cobaltochelatase subunit, putative Short Name  Cob_chelat_sub_put
Type  Family Description  Cobaltochelatase is responsible for the insertion of cobalt into the corrin ring of coenzyme B12 during its biosynthesis. Cobalamin (vitamin B12) can be complexed with metal via ATP-dependent reactions (aerobic pathway) (e.g., in Pseudomonas denitrificans) or via ATP-independent reactions (anaerobic pathway) (e.g., in Salmonella typhimurium) [, ]. The corresponding cobalt chelatases are not homologous. The two versions have been well described. CbiK/CbiX is a monomeric, anaerobic version which acts early in the biosynthesis (). CobNST is a trimeric, ATP-dependent, aerobic version which acts late in the biosynthesis (//). The two pathways differ in the point of cobalt insertion during corrin ring formation []. There are apparently a number of variations on these two pathways, where the major differences seem to be concerned with the process of ring contraction [].A number of genomes (actinobacteria, cyanobacteria, betaproteobacteria and pseudomonads) which apparently biosynthesise B12, encode a cobN gene but are demonstrably lacking cobS and cobT. These genomes do, however contain a homologue, represented by this entry, of the magnesium chelatase subunits BchI/BchD family. Aside from the cyanobacteria (which have a separate magnesium chelatase trimer), these species do not make chlorins, so do not have any use for a magnesium chelatase. Furthermore, in nearly all cases the members of this family are proximal to either CobN itself or other genes involved in cobalt transport or B12 biosynthesis. Cobaltochelatase shows similarities with magnesium chelatase, which is also a complex ATP-dependent enzyme made up of two separable components. However, unlike the situation in cobaltochelatase, one of these two components is membrane bound in magnesium chelatase [].

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

2 Contains

Id Name Short Name Type
IPR002035 von Willebrand factor, type A VWF_A Domain
IPR000523 Magnesium chelatase, ChlI subunit Mg_chelatse_chII Domain

0 Found In

0 Parent Features

4 Publications

First Author Title Year Journal Volume Pages
Raux E Biosynthesis of cobalamin (vitamin B12): a bacterial conundrum. 2000 Cell Mol Life Sci 57 1880-93
Roth JR Cobalamin (coenzyme B12): synthesis and biological significance. 1996 Annu Rev Microbiol 50 137-81
Fodje MN Interplay between an AAA module and an integrin I domain may regulate the function of magnesium chelatase. 2001 J Mol Biol 311 111-22
Walker CJ In vitro assay of the chlorophyll biosynthetic enzyme Mg-chelatase: resolution of the activity into soluble and membrane-bound fractions. 1991 Proc Natl Acad Sci U S A 88 5789-93

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)