Cofactor transferase family

Cofactor transferase domain
The three-dimensional structure of BirA, the repressor of the Escherichia coli biotin biosynthetic operon.[1]
Identifiers
Symbol	BPL
Pfam	PF03099
InterPro	IPR004143
SCOP	1bia
Available protein structures: Pfam structures PDB RCSB PDB; PDBe PDBsum structure summary

In molecular biology, the Cofactor transferase family is a family of protein domains that includes biotin protein ligases, lipoate-protein ligases A, octanoyl-(acyl carrier protein):protein N-octanoyltransferases, and lipoyl-protein:protein N-lipoyltransferases.^[2] The metabolism of the cofactors Biotin and lipoic acid share this family. They also share the target modification domain (Pfam PF00364), and the sulfur insertion enzyme (Pfam PF04055).

Biotin protein ligase (BPL) is the enzyme responsible for attaching biotin to a specific lysine at the biotin carboxyl carrier protein. Each organism likely has only one BPL protein. Biotin attachment is a two step reaction that results in the formation of an amide linkage between the carboxyl group of biotin and the epsilon-amino group of the modified lysine. Biotin attachment is required for biotin biosynthesis and utilization of free biotin.^[3]

Lipoate-protein ligase catalyses the formation of an amide linkage between lipoic acid and a specific lysine residue of the lipoyl domain of lipoate dependent enzymes. They are required for the utilization of free lipoic acid.^[4]

Octanoyl-(acyl carrier protein):protein N-octanoyltransferases, or octanoyltransferases, are required for lipoic acid biosynthesis. They transfer octanoate from the acyl carrier protein (ACP), part of fatty acid biosynthesis, to the specific lysine residue of lipoyl domains.^[5] Two octanoyltransferase isozymes exist in this superfamily.^[6]

Lipoyl-protein:protein N-lipoyltransferases, or lipoylamidotransferases, are required for lipoic acid metabolism in some organsims. They transfer lipoic acid or octanoate from lipoyl domains and transfer to other lipoyl domains. In Bacillus subtilis, the transfer is from the glycine cleavage system H protein, GcvH, to other lipoyl domains. This is because the octanoyltransferase of B. subtilis is specific for GcvH.^[7][8]

Structure

Octanoyltransferases and lipoyl-amidotransferases are single domain enzymes. Characterized lipoate protein ligases require an additional acessory domain (Pfam PF10437) to adenylate the acyl substrate. Biotin protein ligases have an additional C-terminal domain which participates in biotin adenylation and dimerization. Biotin protein ligases may also have an additional N-terminal domain required for DNA binding, although this domain is not always present.^[1][2]

References

1. ^ ^{a b} Wilson KP, Shewchuk LM, Brennan RG, Otsuka AJ, Matthews BW (October 1992). "Escherichia coli biotin holoenzyme synthetase/bio repressor crystal structure delineates the biotin- and DNA-binding domains". Proc. Natl. Acad. Sci. U.S.A. 89 (19): 9257–61. doi:10.1073/pnas.89.19.9257. PMC 50105. PMID 1409631. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=50105. 
2. ^ ^{a b} Reche PA (October 2000). "Lipoylating and biotinylating enzymes contain a homologous catalytic module". Protein Sci. 9 (10): 1922–9. doi:10.1110/ps.9.10.1922. PMC 2144473. PMID 11106165. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2144473. 
3. ^ Chapman-Smith A, Cronan JE (September 1999). "The enzymatic biotinylation of proteins: a post-translational modification of exceptional specificity". Trends Biochem. Sci. 24 (9): 359–63. PMID 10470036. 
4. ^ Morris TW, Reed KE, Cronan JE (June 1994). "Identification of the gene encoding lipoate-protein ligase A of Escherichia coli. Molecular cloning and characterization of the lplA gene and gene product". J. Biol. Chem. 269 (23): 16091–100. PMID 8206909. 
5. ^ Cronan JE, Zhao X, Jiang Y (2005). "Function, attachment and synthesis of lipoic acid in Escherichia coli". Adv. Microb. Physiol. 50: 103–46. doi:10.1016/S0065-2911(05)50003-1. PMID 16221579. 
6. ^ Christensen QH, Cronan JE (2010). "Lipoic acid synthesis: a new family of octanoyltransferases generally annotated as lipoate protein ligases.". Biochemistry 49 (46): 10024–36. doi:10.1021/bi101215f. PMC 2982868. PMID 20882995. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2982868. 
7. ^ Christensen QH, Martin N, Mansilla MC, de Mendoza D, Cronan JE. (2011). "A novel amidotransferase required for lipoic acid cofactor assembly in Bacillus subtilis.". Mol. Microbiol. 80 (2): 350–63. doi:10.1111/j.1365-2958.2011.07598.x. PMC 3088481. PMID 21338421. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3088481. 
8. ^ Martin N, Christensen QH, Mansilla MC, Cronan JE, de Mendoza D. (2011). "A novel two-gene requirement for the octanoyltransfer reaction of Bacillus subtilis lipoic acid biosynthesis.". Mol. Microbiol. 80 (2): 335–49. doi:10.1111/j.1365-2958.2011.07597.x. PMC 3086205. PMID 21338420. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3086205.