1WVR

Crystal Structure of a CRISP family Ca-channel blocker derived from snake venom

Summary for 1WVR

• Entry DOI: 10.2210/pdb1wvr/pdb
• Descriptor: Triflin, CADMIUM ION (3 entities in total)
• Functional Keywords: cysteine-rich secretory protein, toxin
• Biological source: Trimeresurus flavoviridis
• Cellular location: Secreted: Q8JI39
• Total number of polymer chains: 1
• Total formula weight: 25838.61

Authors

Shikamoto, Y.,Suto, K.,Yamazaki, Y.,Morita, T.,Mizuno, H. (deposition date: 2004-12-24, release date: 2005-07-05, Last modification date: 2024-10-23)

Primary citation

Shikamoto, Y.,Suto, K.,Yamazaki, Y.,Morita, T.,Mizuno, H.
Crystal structure of a CRISP family Ca2+ -channel blocker derived from snake venom.
J.Mol.Biol., 350:735-743, 2005

PubMed Abstract: The cysteine-rich secretory proteins (CRISPs) are widely distributed in mammals, reptiles, amphibians and secernenteas, and are involved in a variety of biological reactions. Here we report the crystal structure of triflin, a snake venom derived blocker of high K(+)-induced artery contraction, at 2.4A resolution. Triflin consists of two domains. The first 163 residues form a large globular body with an alpha-beta-alpha sandwich core, which resembles pathogenesis-related proteins of group-1 (PR-1). Two glutamic acid-associated histidine residues are located in an elongated cleft. A Cd(2+) resides in this binding site, and forms a five-coordination sphere. The subsequent cysteine-rich domain adopts a rod-like shape, which is stabilized by five disulfide bridges. Hydrophobic residues, which may obstruct the target ion-channel, are exposed to the solvent. A concave surface, which is surrounded by these two domains, is also expected to play a significant role in the binding to the target receptor, leading to ion channel blockage. The C-terminal cysteine-rich region has a similar tertiary structure to voltage-gated potassium channel blocker toxins, such as BgK and ShK. These findings will contribute toward understanding the functions of the widely distributed CRISP family proteins.

PubMed: 15953617
DOI: 10.1016/j.jmb.2005.05.020

Experimental method

X-RAY DIFFRACTION (2.4 Å)