1KHO	Toxin	date	Nov 30, 2001
title	Crystal Structure Analysis Of Clostridium Perfringens Alpha- Toxin Isolated From Avian Strain Swcp
authors	N.Justin, D.S.Moss, R.W.Titball, A.K.Basak
compound		source
Molecule: Alpha-Toxin Chain: A, B Engineered: Yes		Organism_scientific: Clostridium Perfringens Organism_common: Bacteria Gene: Cpa Expression_system: Escherichia Coli Expression_system_common: Bacteria Expression_system_strain: Bl21
symmetry	Space Group: P 41 2 2	R_factor	0.210
crystal cell	length a length b length c angle alpha angle beta angle gamma 117.230 117.230 220.590 90.00 90.00 90.00
method	X-Ray Diffraction	resolution	2.40 Å
ligand	ZN	enzyme
related structures	by homologous chain: 1OLP, 1QM6, 1QMD
domain	The c-terminal domain is a putative phospholipid-recognition domain, which shows structural homology with phospholipid-binding c2-like domains from a range of eukaryotic proteins. The protein is composed of 2 domains; the n-terminal domain contains the phospholipase c active site (plc), in a cleft which is also occupied by the 3 zinc ions. The ability to bind membrane phospholipids in a ca(2+) dependent manner and toxicity is conferred by this c-terminal domain, which also contributes to the sphingomyelinase activity.
similarity	Contains 1 plat domain.[Zn_dep_PLPC]
catalytic activ.	A phosphatidylcholine + h(2)o = 1,2- diacylglycerol + choline phosphate.
subcellular loc.	Membrane localization by OPM: Secreted out side in side
Genes	CPA, PLC (C. perfringens)
function	Binds to eukaryotic membranes where it hydrolyzes both phosphatidylcholine and sphingomyelin, causing cell rupture. The diacylglycerol produced can activate both the arachidonic acid pathway, leading to modulation of the inflammatory response cascade and thrombosis, and protein kinase c, leading to activation of eukaryotic phospholipases and further membrane damage. Bacterial hemolysins are exotoxins that attack blood cell membranes and cause cell rupture. Constitutes an essential virulence factor in gas gangrene.
Gene Ontology	Chain Function Process Component A, B phospholipase C activity calcium ion binding zinc ion binding hydrolase activity metal ion binding pathogenesis cytolysis hemolysis by symbiont of hos...
Primary reference	The first strain of Clostridium perfringens isolated from an avian source has an alpha-toxin with divergent structural and kinetic properties., Justin N, Walker N, Bullifent HL, Songer G, Bueschel DM, Jost H, Naylor C, Miller J, Moss DS, Titball RW, Basak AK, Biochemistry 2002 May 21;41(20):6253-62. PMID:12009886

Data retrieval

Asymmetric unit, PDB entry: [header only] [complete with coordinates] (126 Kb) [Save to disk] Biological Unit Coordinates (1kho.pdb1.gz) 64 Kb Biological Unit Coordinates (1kho.pdb2.gz) 61 Kb CSU: Contacts of Structural Units for 1KHO Likely Quarternary Molecular Structure file(s) for 1KHO Retrieve 1KHO in mmCIF format [Save to disk]

View 1KHO in 3D

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Visual 3D analysis of 1KHO

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Structure-derived information

Dipole moment, from Dipole Server at Weizmann Institute Crystal Contacts, from CryCo at Weizmann Institute 3D motif for 1KHO, from MSDmotif at EBI Classification of representative domains in scop (Structural Classification of Proteins)     - Domain d1khoa1, region A:1-249 [Jmol] [rasmolscript] [script source]     - Domain d1khoa2, region A:250-370 [Jmol] [rasmolscript] [script source]     - Domain d1khob1, region B:1-249 [Jmol] [rasmolscript] [script source]     - Domain d1khob2, region B:250-370 [Jmol] [rasmolscript] [script source] Fold representative 1kho from FSSP and Dali (Families of Structurally Similar Proteins) Class (fold), Architecture (subfold), Topology, Homologous superfamily from CATH Summaries and structural analyses of PDB data files from PDBSum Identification of Protein Pockets & Cavities at CASTp

Sequence-derived information

View one-letter amino acid or nucleotide sequence for each chain: [1kho_A] [1kho_B]

Other resources with information on 1KHO

InterPro: IPR001024 , IPR008976 , IPR001531 PDBREPORT (protein verification by WHAT_CHECK procedures) MMDB (Entrez's Structure Database)

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