2AB9

Discovery, structural determination and processing of the precursor protein that produces the cyclic trypsin inhibitor SFTI-1

2AB9 の概要

• エントリーDOI: 10.2210/pdb2ab9/pdb
• 分子名称: pro-SFTI-1 (1 entity in total)
• 機能のキーワード: protein, beta-sheet, random coil, hydrolase inhibitor
• 由来する生物種: Helianthus annuus (common sunflower)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 3371.84

構造登録者

Mulvenna, J.P.,Foley, F.M.,Craik, D.J. (登録日: 2005-07-15, 公開日: 2005-07-26, 最終更新日: 2024-10-16)

主引用文献

Mulvenna, J.P.,Foley, F.M.,Craik, D.J.
Discovery, structural determination and putative processing of the precursor protein that produces the cyclic trypsin inhibitor SFTI-1
J.Biol.Chem., 280:32245-32253, 2005

PubMed Abstract: Backbone-cyclized proteins are becoming increasingly well known, although the mechanism by which they are processed from linear precursors is poorly understood. In this report the sequence and structure of the linear precursor of a cyclic trypsin inhibitor, sunflower trypsin inhibitor 1 (SFTI-1) from sunflower seeds, is described. The structure indicates that the major elements of the reactive site loop of SFTI-1 are present before processing. This may have importance for a protease-mediated cyclizing reaction as the rigidity of SFTI-1 may drive the equilibrium of the reaction catalyzed by proteolytic enzymes toward the formation of a peptide bond rather than the normal cleavage reaction. The occurrence of residues in the SFTI-1 precursor susceptible to cleavage by asparaginyl proteases strengthens theories that involve this enzyme in the processing of SFTI-1 and further implicates it in the processing of another family of plant cyclic proteins, the cyclotides. The precursor reported here also indicates that despite strong active site sequence homology, SFTI-1 has no other similarities with the Bowman-Birk trypsin inhibitors, presenting interesting evolutionary questions.

PubMed: 16036912
DOI: 10.1074/jbc.M506060200

実験手法

SOLUTION NMR