1qh2
From Proteopedia
CHYMOTRYPSIN INHIBITOR (C2) FROM NICOTIANA ALATA
Overview
Female reproductive tissues of the ornamental tobacco amass high levels of serine proteinase inhibitors (PIs) for protection against pests and pathogens. These PIs are produced from a precursor protein composed of six repeats each with a protease reactive site. Here we show that proteolytic processing of the precursor generates five single-chain PIs and a remarkable two-chain inhibitor formed by disulfide-bond linkage of N- and C-terminal peptide fragments. Surprisingly, PI precursors adopt this circular structure regardless of the number of inhibitor domains, suggesting this bracelet-like conformation is characteristic of the widespread potato inhibitor II (Pot II) protein family.
About this Structure
1QH2 is a Protein complex structure of sequences from Nicotiana alata. Full crystallographic information is available from OCA.
Reference
A novel two-chain proteinase inhibitor generated by circularization of a multidomain precursor protein., Lee MC, Scanlon MJ, Craik DJ, Anderson MA, Nat Struct Biol. 1999 Jun;6(6):526-30. PMID:10360353 Page seeded by OCA on Sat May 3 06:15:48 2008
