1STF

THE REFINED 2.4 ANGSTROMS X-RAY CRYSTAL STRUCTURE OF RECOMBINANT HUMAN STEFIN B IN COMPLEX WITH THE CYSTEINE PROTEINASE PAPAIN: A NOVEL TYPE OF PROTEINASE INHIBITOR INTERACTION

1STF の概要

• エントリーDOI: 10.2210/pdb1stf/pdb
• 分子名称: PAPAIN, STEFIN B (CYSTATIN B) (3 entities in total)
• 機能のキーワード: hydrolase(sulfhydryl proteinase)
• 由来する生物種: Carica papaya (papaya); 詳細
• 細胞内の位置: Cytoplasm : P04080
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 34680.95

構造登録者

Stubbs, M.T.,Laber, B.,Bode, W. (登録日: 1993-04-21, 公開日: 1994-01-31, 最終更新日: 2025-03-26)

主引用文献

Stubbs, M.T.,Laber, B.,Bode, W.,Huber, R.,Jerala, R.,Lenarcic, B.,Turk, V.
The refined 2.4 A X-ray crystal structure of recombinant human stefin B in complex with the cysteine proteinase papain: a novel type of proteinase inhibitor interaction.
EMBO J., 9:1939-1947, 1990

PubMed Abstract: A stoichiometric complex of human stefin B and carboxymethylated papain has been crystallized in a trigonal crystal form. Data to 2.37 A resolution were collected using the area detector diffractometer FAST. The crystal structure of the complex has been solved by Patterson search techniques using papain as search model. Starting from the structure of chicken cystatin, the stefin structure was elucidated through cycles of model building and crystallographic refinement. The current crystallographic R factor is 0.19. Like cystatin, the stefin molecule consists of a five stranded beta-sheet wrapped around a five turn alpha-helix, but with an additional carboxy terminal strand running along the convex side of the sheet. Topological equivalence of stefin and cystatin reveal the previous sequence alignment to be incorrect in part, through deletion of the intermediate helix. The conserved residues form a tripartite wedge, which slots into the papain active site as proposed through consideration of the tertiary structures of the individual components (Bode et al., 1988). The main interactions are provided by the amino terminal 'trunk' (occupying the 'unprimed' subsites of the enzyme), and by the first hairpin loop, containing the highly conserved QVVAG sequence, with minor contributions from the second hairpin loop. The carboxyl terminus of stefin provides an additional interaction region with respect to cystatin. The interaction is dominated by hydrophobic contacts. Inhibition by the cysteine proteinase inhibitors is fundamentally different to that observed for the serine proteinase inhibitors.

PubMed: 2347312

実験手法

X-RAY DIFFRACTION (2.37 Å)