Catalyzes the transfer of biotin onto a conserved lysine residue of the biotin carboxyl carrier protein (BCCP) domain of acetyl-CoA carboxylase and converts it to active holo-BCCP (PubMed:18509457, PubMed:24723382). Forms an acyl-adenylate intermediate (PubMed:18509457, PubMed:24723382). Cannot use GTP or desthiobiotin (PubMed:18509457). ATP + biotin + L-lysyl-[protein] = AMP + diphosphate + H(+) + N(6)-biotinyl-L-lysyl-[protein] ATP + biotin + H(+) = biotinyl-5'-AMP + diphosphate biotinyl-5'-AMP + L-lysyl-[protein] = AMP + 2 H(+) + N(6)-biotinyl-L-lysyl-[protein] Binding of biotin and ATP significantly increases the thermal stability of BirA and leads to the formation of a high affinity holoenzyme complex. kcat is 0.034 sec(-1) with biotin as substrate. kcat is 0.0282 sec(-1) with Mg/ATP as substrate. kcat is 0.030 sec(-1) with apo-BCCP as substrate (PubMed:18509457). kcat is 0.017 sec(-1) with ATP as substrate (PubMed:24723382). Optimum pH is 7.5-8.0. Monomer in solution (PubMed:18509457, PubMed:20169168, PubMed:24723382). Forms dimers under specific crystallization conditions (PubMed:18540066, PubMed:20169168). Belongs to monofunctional group I BPL as it lacks the N-terminal helix-turn-helix (HTH) DNA-binding domain. Identified as a drug target (PubMed:22118677, PubMed:26299766, PubMed:28942842). Inhibited by Bio-AMS, an acylsulfamide bisubstrate inhibitor, and analogs (PubMed:22118677, PubMed:26299766). Bio-AMS displays potent subnanomolar enzyme inhibition and antitubercular activity against multidrug resistant and extensively drug resistant Mtb strains (PubMed:22118677). Belongs to the biotin--protein ligase family.