1OLP

Alpha Toxin from Clostridium Absonum

1OLP の概要

• エントリーDOI: 10.2210/pdb1olp/pdb
• 分子名称: ALPHA-TOXIN, CALCIUM ION, ZINC ION, ... (4 entities in total)
• 機能のキーワード: zinc phospholipase c, gas gangrene determinant, membrane binding, calcium binding, hydrolase
• 由来する生物種: CLOSTRIDIUM SARDINIENSE
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 172120.66

構造登録者

Briggs, D.C.,Basak, A.K. (登録日: 2003-08-11, 公開日: 2003-10-23, 最終更新日: 2023-12-13)

主引用文献

Clark, G.,Briggs, D.C.,Karasawa, T.,Wang, X.,Cole, A.,Maegawa, T.,Jayasekera, P.,Naylor, C.,Miller, J.,Moss, D.,Nakamura, S.,Basak, A.K.,Titball, R.
Clostridium Absonum Alpha-Toxin: New Insights Into Clostridial Phospholipase C Substrate Binding and Specificity
J.Mol.Biol., 333:759-, 2003

PubMed Abstract: Clostridium absonum phospholipase C (Caa) is a 42.7 kDa protein, which shows 60% amino acid sequence identity with the Clostridium perfringens phospholipase C, or alpha-toxin (Cpa), and has been isolated from patients suffering from gas gangrene. We report the cloning and sequencing, purification, characterisation and crystal structure of the Caa enzyme. Caa had twice the phospholipid-hydrolysing (lecithinase) activity, 1.5 times the haemolytic activity and over seven times the activity towards phosphatidylcholine-based liposomes when compared with Cpa. However, the Caa enzyme had a lower activity than Cpa to the free (i.e. not in lipid bilayer) substrate para-nitrophenylphosphorylcholine, towards sphingomyelin-based liposomes and showed half the cytotoxicity. The lethal dose (LD(50)) of Caa in mice was approximately twice that of Cpa. The crystal structure of Caa shows that the 72-93 residue loop is in a conformation different from those of previously determined open-form alpha-toxin structures. This conformational change suggests a role for W84 in membrane binding and a possible route of entry into the active site along a hydrophobic channel created by the re-arrangement of this loop. Overall, the properties of Caa are compatible with a role as a virulence-determinant in gas gangrene caused by C.absonum.

PubMed: 14568535
DOI: 10.1016/J.JMB.2003.07.016

実験手法

X-RAY DIFFRACTION (2.5 Å)