A novel two-chain proteinase inhibitor generated by circularization of a multidomain precursor protein

M. C.S. Lee, M. J. Scanlon, D. J. Craik, M. A. Anderson

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54 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)526-530
Number of pages5
JournalNature Structural Biology
Issue number6
Publication statusPublished - 9 Jun 1999
Externally publishedYes

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