1XX5
Crystal Structure of Natrin from Naja atra snake venom
Summary for 1XX5
| Entry DOI | 10.2210/pdb1xx5/pdb |
| Descriptor | Natrin 1, ETHANOL (3 entities in total) |
| Functional Keywords | natrin, crisps, naja atra, toxin |
| Biological source | Naja atra (Chinese cobra) |
| Cellular location | Secreted: Q7T1K6 |
| Total number of polymer chains | 3 |
| Total formula weight | 75035.40 |
| Authors | |
| Primary citation | Wang, J.,Shen, B.,Guo, M.,Lou, X.H.,Duan, Y.,Cheng, X.P.,Teng, M.K.,Niu, L.W.,Liu, Q.,Huang, Q.,Hao, Q. Blocking effect and crystal structure of natrin toxin, a cysteine-rich secretory protein from Naja atra venom that targets the BKCa channel Biochemistry, 44:10145-10152, 2005 Cited by PubMed Abstract: Cysteine-rich secretory proteins (CRISPs) are widespread in snake venoms. Some members of these CRISPs recently have been found to block L-type Ca(2+) channels or cyclic nucleotide-gated ion (CNG) channels. Here, natrin purified from Naja atra venom, a member of the CRISP family, can induce a further contractile response in the endothelium-denuded thoracic aorta of mouse which has been contracted by a high-K(+) solution. Further experiments show it can block the high-conductance calcium-activated potassium (BK(Ca)) channel in a concentration-dependent manner with an IC(50) of 34.4 nM and a Hill coefficient of 1.02, which suggests that only a single natrin molecule is required to bind an ion channel to block BK(Ca) current. The crystal structure of natrin displaying two domains in tandem shows its cysteine-rich domain (CRD) has relatively independent flexibility, especially for the C-terminal long loop (loop I) of CRD to participate in the interface of two domains. On the basis of previous studies of CNG channel and L-Ca(2+) channel blockers, and the sequence and structural comparison of natrin and stecrisp, the deviation of the vital loop I of CRD is suggested to contribute to different effects of some CRISPs in protein-protein interaction. PubMed: 16042391DOI: 10.1021/bi050614m PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.4 Å) |
Structure validation
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