Protein Family Models

Members of this family are involved in cobalamin synthesis. The gene encoded by Swiss:P72862 has been designated cbiH but in fact represents a fusion between cbiH and cbiG. As other multi-functional proteins involved in cobalamin biosynthesis catalyse adjacent steps in the pathway, including CysG, CobL (CbiET), CobIJ and CobA-HemD, it is therefore possible that CbiG catalyses a reaction step adjacent to CbiH. In the anaerobic pathway such a step could be the formation of a gamma lactone, which is thought to help to mediate the anaerobic ring contraction process [1]. [1]. 9742225. Cobalamin (vitamin B12) biosynthesis: identification and characterization of a Bacillus megaterium cobI operon. Raux E, Lanois A, Warren MJ, Rambach A, Thermes C;. Biochem J 1998;335:159-166. (from Pfam)

Date:

2024-10-16

Members of this family are involved in cobalamin synthesis. The gene encoded by Swiss:P72862 has been designated cbiH but in fact represents a fusion between cbiH and cbiG. As other multi-functional proteins involved in cobalamin biosynthesis catalyse adjacent steps in the pathway, including CysG, CobL (CbiET), CobIJ and CobA-HemD, it is therefore possible that CbiG catalyses a reaction step adjacent to CbiH. In the anaerobic pathway such a step could be the formation of a gamma lactone, which is thought to help to mediate the anaerobic ring contraction process [1]. Within the cobalamin synthesis pathway CbiG catalyses the both the opening of the lactone ring and the extrusion of the two-carbon fragment of cobalt-precorrin-5A from C-20 and its associated methyl group (deacylation) to give cobalt-precorrin-5B [2]. The N-terminal of the enzyme is conserved in this family, and the C-terminal and the mid-sections are conserved independently in other families, CbiG_C and CbiG_mid, although the distinct function of each region is unclear. [1]. 9742225. Cobalamin (vitamin B12) biosynthesis: identification and characterization of a Bacillus megaterium cobI operon. Raux E, Lanois A, Warren MJ, Rambach A, Thermes C;. Biochem J 1998;335:159-166. [2]. 16866557. Genetically engineered synthesis and structural characterization of cobalt-precorrin 5A and -5B, two new intermediates on the anaerobic pathway to vitamin B12: definition of the roles of the CbiF and CbiG enzymes. Kajiwara Y, Santander PJ, Roessner CA, Perez LM, Scott AI;. J Am Chem Soc. 2006;128:9971-9978. (from Pfam)

Date:

2024-10-16

Members of this family are involved in cobalamin synthesis. The gene encoded by Swiss:P72862 has been designated cbiH but in fact represents a fusion between cbiH and cbiG. As other multi-functional proteins involved in cobalamin biosynthesis catalyse adjacent steps in the pathway, including CysG, CobL (CbiET), CobIJ and CobA-HemD, it is therefore possible that CbiG catalyses a reaction step adjacent to CbiH. In the anaerobic pathway such a step could be the formation of a gamma lactone, which is thought to help to mediate the anaerobic ring contraction process [1]. Within the cobalamin synthesis pathway CbiG catalyses the both the opening of the lactone ring and the extrusion of the two-carbon fragment of cobalt-precorrin-5A from C-20 and its associated methyl group (deacylation) to give cobalt-precorrin-5B [2]. This family is the C-terminal region, and the mid- and N-termival parts are conserved independently in other families. [1]. 9742225. Cobalamin (vitamin B12) biosynthesis: identification and characterization of a Bacillus megaterium cobI operon. Raux E, Lanois A, Warren MJ, Rambach A, Thermes C;. Biochem J 1998;335:159-166. [2]. 16936030. Fine-tuning our knowledge of the anaerobic route to cobalamin (vitamin B12). Roessner CA, Scott AI;. J Bacteriol. 2006;188:7331-7334. (from Pfam)

Date:

2024-10-16

cobalt-precorrin 5A hydrolase catalyzes the hydrolysis of the ring A acetate delta-lactone of cobalt-precorrin-5A, resulting in the loss of the C-20 carbon and its attached methyl group in the form of acetaldehyde

Date:

2019-10-25