Biotinyl protein ligase (BPL) and lipoyl protein ligase (LPL), catalytic domain (IPR004143)

Short name: BPL_LPL_catalytic

Overlapping homologous superfamilies


Domain relationships



Biotin and lipoic acid are the covalently bound cofactors of various multicomponent enzyme complexes that catalyze key metabolic reactions. In these enzymes complexes, biotin and lipoic acid are attached via amide linkage through their carboxyl group and the epsilon-amino group of a specific lysine residue of a protein module known respectively as the biotinyl and the lipoyl domain. Covalent attachment of biotin and lipoic acid to these enzyme complexes occurs post-translationally, and it is mediated by biotinylating and lipoylating protein enzymes, which specifically recognise the biotinyl and lipoyl domains, ensuring their correct post-translational modification. Lipoylating and biotinylating enzymes are evolutionarily related protein families containing a homologous catalytic module [PMID: 11106165].

Amino acid sequence conservation between the catalytic modules of biotinyl protein ligases (BPLs) and lipoyl protein ligases (LPLs) is very low, and mainly affects residues that are important for the scaffold of the structure, such as those contributing to the hydrophobic core. Despite the poor overall sequence similarity, a single lysine residue is strictly conserved in all LPL and BPL sequences. This lysine residue is likely to bind specifically to the carbonyl oxygen of the carboxyl group of biotin or at the end of the hydrogen- carbon tail of the lipoyl moiety [PMID: 11106165]. The BPL/LPL catalytic domain contains a seven-stranded mixed beta-sheet on one side and four alpha-helices on the other side [PMID: 16169557].

GO terms

Biological Process

GO:0006464 cellular protein modification process

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles