Figure 2: Multiple sequence alignments of HCS proteins. The highly conserved sequences of HCS proteins among different organisms were aligned using CLUSTALX [27]. Eight amino acids labeled by red boxes are required for biotin ligation according to the BirA crystal structure [22]. The BPL_lipA/B and BPL_C domains are underlined in green and orange, respectively. Δ is location of Y663 mutation in a patient with HCS deficiency.