1ym0
From Proteopedia
Crystal Structure of Earthworm Fibrinolytic Enzyme Component B: a Novel, Glycosylated Two-chained Trypsin
Overview
The earthworm fibrinolytic enzyme (EFE), belonging to a group of serine proteases with strong fibrinolytic activity, has been used in a mixture as an oral drug for prevention and treatment of thrombosis in East Asia. The EFE component b (EFE-b) is one of seven EFE components from Eisenia fetida, and among them it has nearly the highest fibrinolytic activity. Here, we report its crystal structure at a resolution of 2.06A. The structural analysis shows that EFE-b should be classified as a trypsin from earthworm. However, it is distinct from other trypsins. It is a two-chained protease with an N-terminal, pyroglutamated light chain and an N-glycosylated heavy chain. Furthermore, the heavy chain contains a novel structural motif, an eight-membered ring resulting from a disulfide bridge between two neighboring cysteine residues, and a cis peptide bond exists between these two cysteine residues. The crystal structure of EFE-b provides the structural basis for its high level of stability and reveals its complicated post-translational modifications in earthworm. This structure is the first reported for a glycosylated two-chained trypsin, which may provide useful clues to explain the origin and evolution of the chymotrypsin family.
About this Structure
Full crystallographic information is available from OCA.
Reference
Crystal structure of earthworm fibrinolytic enzyme component B: a novel, glycosylated two-chained trypsin., Wang F, Wang C, Li M, Zhang JP, Gui LL, An XM, Chang WR, J Mol Biol. 2005 May 6;348(3):671-85. PMID:15826663 Page seeded by OCA on Sat May 3 16:29:39 2008
