Crystal Structure of Candida antarctica Lipase B with a Putative Pro-Peptide Region

There are 25 crystal structures of Lipase B from Candida antarctica (CalB) that have been previously reported. In this study, we report the first CalB crystal structure that shows the assumed pro-peptide region at the N-terminus (Ala19–Arg25). This 1.45 Å structure shows that this segment of seven amino acids is an extension of the N-terminal loop and that it does not interact with or effect conformational changes in the flexible lid domain, which covers the active site of the enzyme. As such, this region is unlikely to be a classical pro-peptide.