Sequence conservation in the chagasin family suggests a common trend in cysteine proteinase binding by unrelated protein inhibitors.

ABSTRACT: The recently described inhibitor of cysteine proteinases from Trypanosoma cruzi, chagasin, was found to have close homologs in several eukaryotes, bacteria and archaea, the first protein inhibitors of cysteine proteases in prokaryotes. These previously uncharacterized 110-130 residue-long proteins share a well-conserved sequence motif that corresponds to two adjacent beta-strands and the short loop connecting them. Chagasin-like proteins also have other conserved, mostly aromatic, residues, and share the same predicted secondary structure. These proteins adopt an all-beta fold with eight predicted beta-strands of the immunoglobulin type. The phylogenetic distribution of the chagasins generally correlates with the presence of papain-like cysteine proteases. Previous studies have uncovered s

SUBMITTER: Rigden DJ 

PROVIDER: S-EPMC2373688 | biostudies-literature | 2002 Aug

REPOSITORIES: biostudies-literature