X-RAY STRUCTURE AT 1.55 A OF TOXIN GAMMA, A CARDIOTOXIN FROM NAJA NIGRICOLLIS VENOM. CRYSTAL PACKING REVEALS A MODEL FOR INSERTION INTO MEMBRANESX-RAY STRUCTURE AT 1.55 A OF TOXIN GAMMA, A CARDIOTOXIN FROM NAJA NIGRICOLLIS VENOM. CRYSTAL PACKING REVEALS A MODEL FOR INSERTION INTO MEMBRANES

Structural highlights

1tgx is a 3 chain structure with sequence from Naja nigricollis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.55Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

3SA1_NAJPA Basic protein that binds to cell membrane and depolarizes cardiomyocytes. This cytotoxin also possesses lytic activity on many other cells, including red blood cells. Interaction with sulfatides in the cell membrane induces pore formation and cell internalization and is responsible for cytotoxicity in cardiomyocytes. It targets the mitochondrial membrane and induces mitochondrial swelling and fragmentation. Inhibits protein kinases C. It binds to the integrin alpha-V/beta-3 with a moderate affinity.[UniProtKB:P01443]

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The crystal structure of toxin gamma from Naja nigricollis has been solved and refined to 1.55 A resolution. The final R-factor, computed with all X-ray data available, is 17.9%. The three-dimensional structure is characterized by a core formed by two beta-sheets organized in three extended loops. It is similar to that of cardiotoxin V4II from Naja mossambica mossambica, with the exception of the hydrophobic loop I. The flexibility and variability of the loops contrast sharply with the rigidity of the molecular core and its high degree of structural conservation among the cardiotoxin family. The most flexible loop II adopts different conformations in the three monomers forming the crystal asymmetric unit. These monomers form a trimer around an approximate 3-fold axis, with conserved hydrophobic side-chains on the outside and hydrophilic residues in the central channel or involved in interactions with the other molecules. The trimer thus resembles a membrane protein with a central channel that could allow the passage of small ions. It is proposed as a model for the insertion of cardiotoxin into a membrane.

X-ray structure at 1.55 A of toxin gamma, a cardiotoxin from Naja nigricollis venom. Crystal packing reveals a model for insertion into membranes.,Bilwes A, Rees B, Moras D, Menez R, Menez A J Mol Biol. 1994 May 27;239(1):122-36. PMID:8196041[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Bilwes A, Rees B, Moras D, Menez R, Menez A. X-ray structure at 1.55 A of toxin gamma, a cardiotoxin from Naja nigricollis venom. Crystal packing reveals a model for insertion into membranes. J Mol Biol. 1994 May 27;239(1):122-36. PMID:8196041 doi:http://dx.doi.org/10.1006/jmbi.1994.1357

1tgx, resolution 1.55Å

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