cd06850: biotinyl_attach (This model is not part of the current CDD release)
the biotinyl attachment domain family
The biotinyl attachment domain, also known as biotin carboxyl carrier protein (BCCP) domain, is a protein module that typically consists of a flattened beta-barrel structure, featuring a conserved lysine residue within a beta-turn where biotin is attached via an amide linkage. This domain functions in transferring CO2 from one subsite to another, allowing carboxylation, decarboxylation, or transcarboxylation. It is specifically recognized by biotin protein ligase (BPL), also known as holocarboxylase synthetase, which attaches the biotin molecule to the lysine residue of the domain in a two-step process, biotin activation and biotinyl group transfer. In multidomain enzymes, the biotinyl attachment domain acts as a flexible arm, shuttling the attached biotin between different active sites to facilitate catalytic reactions. The domain's ability to bind biotin is crucial for its role in various cellular processes, including fatty acid synthesis. The structure of the biotinoyl domain is very similar to that of lipoyl domains, which bind the cofactor lipoic acid.
Feature 1: biotinylation site [posttranslational modification site], 1 residue position
Conserved feature residue pattern:K
Evidence:
Structure:1BDO; Escherichia coli acetyl-coenzyme A carboxylase with covalently bound biotin
Comment:The highly conserved lysine residue serves as the covalent attachment site for either biotin or lipoic acid in the biotin/lipoyl attachment domain superfamily.
Jiyao W et al.(2023). "The conserved domain database in 2023.",