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A Common Structural Motif Incorporating a Cystine Knot and a Triple-stranded Beta-sheet in Toxic and Inhibitory Polypeptides

Overview
Journal Protein Sci
Specialty Biochemistry
Date 1994 Oct 1
PMID 7849598
Citations 151
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Abstract

A common structural motif consisting of a cystine knot and a small triple-stranded beta-sheet has been defined from comparison of the 3-dimensional structures of the polypeptides omega-conotoxin GVIA (Conus geographus), kalata BI (Oldenlandia affinis DC), and CMTI-I (Curcurbita maxima). These 3 polypeptides have diverse biological activities and negligible amino acid sequence identity, but each contains 3 disulfide bonds that give rise to a cystine knot. This knot consists of a ring formed by the first 2 bonds (1-4 and 2-5) and the intervening polypeptide backbone, through which the third disulfide (3-6) passes. The other component of this motif is a triple-stranded, anti-parallel beta-sheet containing a minimum of 10 residues, XXC2, XC5X, XXC6X (where the numbers on the half-cysteine residues refer to their positions in the disulfide pattern). The presence in these polypeptides of both the cysteine knot and antiparallel beta-sheet suggests that both structural features are required for the stability of the motif. This structural motif is also present in other protease inhibitors and a spider toxin. It appears to be one of the smallest stable globular domains found in proteins and is commonly used in toxins and inhibitors that act by blocking the function of larger protein receptors such as ion channels or proteases.

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References
1.
Kamei K, Takano R, Miyasaka A, Imoto T, Hara S . Amino acid sequence of sweet-taste-suppressing peptide (gurmarin) from the leaves of Gymnema sylvestre. J Biochem. 1992; 111(1):109-12. DOI: 10.1093/oxfordjournals.jbchem.a123705. View

2.
Le-Nguyen D, Heitz A, Chiche L, el Hajji M, Castro B . Characterization and 2D NMR study of the stable [9-21, 15-27] 2 disulfide intermediate in the folding of the 3 disulfide trypsin inhibitor EETI II. Protein Sci. 1993; 2(2):165-74. PMC: 2142350. DOI: 10.1002/pro.5560020205. View

3.
Benham C, Jafri M . Disulfide bonding patterns and protein topologies. Protein Sci. 1993; 2(1):41-54. PMC: 2142305. DOI: 10.1002/pro.5560020105. View

4.
Rees D, Lipscomb W . Structure of the potato inhibitor complex of carboxypeptidase A at 2.5-A resolution. Proc Natl Acad Sci U S A. 1980; 77(8):4633-7. PMC: 349899. DOI: 10.1073/pnas.77.8.4633. View

5.
Nilges M, Habazettl J, Brunger A, Holak T . Relaxation matrix refinement of the solution structure of squash trypsin inhibitor. J Mol Biol. 1991; 219(3):499-510. DOI: 10.1016/0022-2836(91)90189-d. View