1HVW
HAIRPINLESS MUTANT OF OMEGA-ATRACOTOXIN-HV1A
Summary for 1HVW
| Entry DOI | 10.2210/pdb1hvw/pdb |
| Related | 1AXH |
| Descriptor | OMEGA-ATRACOTOXIN-HV1A (1 entity in total) |
| Functional Keywords | cystine knot, beta-hairpin, toxin |
| Cellular location | Secreted: P56207 |
| Total number of polymer chains | 1 |
| Total formula weight | 2623.90 |
| Authors | Fletcher, J.I.,King, G.F. (deposition date: 2001-01-08, release date: 2001-01-17, Last modification date: 2024-11-06) |
| Primary citation | Tedford, H.W.,Fletcher, J.I.,King, G.F. Functional significance of the beta hairpin in the insecticidal neurotoxin omega-atracotoxin-Hv1a. J.Biol.Chem., 276:26568-26576, 2001 Cited by PubMed Abstract: omega-Atracotoxin-Hv1a is an insect-specific neurotoxin whose phylogenetic specificity derives from its ability to antagonize insect, but not vertebrate, voltage-gated calcium channels. In order to help understand its mechanism of action and to enhance its utility as a lead compound for insecticide development, we used a combination of protein engineering and site-directed mutagenesis to probe the toxin for key functional regions. First, we constructed a Hairpinless mutant in which the C-terminal beta-hairpin, which is highly conserved in this family of neurotoxins, was excised without affecting the fold of the residual disulfide-rich core of the toxin. The Hairpinless mutant was devoid of insecticidal activity, indicating the functional importance of the hairpin. We subsequently developed a highly efficient system for production of recombinant toxin and then probed the hairpin for key functional residues using alanine-scanning mutagenesis followed by a second round of mutagenesis based on initial "hits" from the alanine scan. This revealed that two spatially proximal residues, Asn(27) and Arg(35), form a contiguous molecular surface that is essential for toxin activity. We propose that this surface of the beta-hairpin is a key site for interaction of the toxin with insect calcium channels. PubMed: 11313356DOI: 10.1074/jbc.M102199200 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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