Reaction: a carboxybiotinyl-[protein] + n Na+[side 1] + H+[side 2] = CO2 + a biotinyl-[protein] + n Na+[side 2] (n = 1-2)
For diagram of the reaction click here
Other name(s): MadB; carboxybiotin protein decarboxylase
Systematic name: carboxybiotinyl-[protein] carboxy-lyase
Comments: The integral membrane protein MadB from the anaerobic bacterium Malonomonas rubra is a component of the multienzyme complex EC 18.104.22.168, biotin-dependent malonate decarboxylase. The free energy of the decarboxylation reaction is used to pump Na+ out of the cell. The enzyme is a member of the Na+-translocating decarboxylase family, other members of which include EC 22.214.171.124 [oxaloacetate decarboxylase (Na+ extruding)] and EC 126.96.36.199 [(S)-methylmalonyl-CoA decarboxylase (sodium-transporting)] .
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
1. Berg, M., Hilbi, H. and Dimroth, P. Sequence of a gene cluster from Malonomonas rubra encoding components of the malonate decarboxylase Na+ pump and evidence for their function. Eur. J. Biochem. 245 (1997) 103-115. [PMID: 9128730]
2. Dimroth, P. and Hilbi, H. Enzymic and genetic basis for bacterial growth on malonate. Mol. Microbiol. 25 (1997) 3-10. [PMID: 11902724]