Alignment of reactive center loop sequences of CBG variants and of closely related AAT.

<p>The RCL sequence shows a high degree of variance even within closely related proteins. The numbering of residues in the RCL of SERPINs is commonly in relation to the normal cleavage site in AAT between P1 and P1′. Already known cleavage sites are shown with grey boxes. The new cleavage site in human CBG observed in the structure is depicted in green. Introduced mutations in rat CBG-RCL1 through RCL3 are marked by orange boxes. The variant marked with an asterix bears in addition two mutations in the top of β-sheet A deleting a salt-bridge by converting it to amino acids present in human CBG (D323N, R174K). The wild-type protein sequences are annotated in the Uniprot knowledgebase with the following accession codes: rat CBG, P31211; human CBG, P08185; human AAT; P01009. The amino acids in the RCL are numbered following the convention of Schechter and Berger, 1967 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052759#pone.0052759-Schechter1" target="_blank">[49]</a>.