2EFZ

Solution Structure of an M-1 Conotoxin with a novel disulfide linkage

Summary for 2EFZ

• Entry DOI: 10.2210/pdb2efz/pdb
• Related: 1E76 1GIB 1KCP 1RMK
• NMR Information: BMRB: 15195
• Descriptor: M conotoxin Mr3.4 (1 entity in total)
• Functional Keywords: m-conotoxin mr3e, toxin
• Cellular location: Secreted: Q5EHP3
• Total number of polymer chains: 1
• Total formula weight: 1753.08

Authors

Fang, W.H.,Du, W.H.,Han, Y.H.,Huang, F.J. (deposition date: 2007-02-26, release date: 2007-05-08, Last modification date: 2024-10-16)

Primary citation

Du, W.H.,Han, Y.H.,Huang, F.J.,Li, J.,Chi, C.W.,Fang, W.H.
Solution structure of an M-1 conotoxin with a novel disulfide linkage
Febs J., 274:2596-2602, 2007

PubMed Abstract: The M-superfamily of conotoxins has a typical Cys framework (-CC-C-C-CC-), and is one of the eight major superfamilies found in the venom of the cone snail. Depending on the number of residues located in the last Cys loop (between Cys4 and Cys5), the M-superfamily family can be divided into four branches, namely M-1, -2, -3 and -4. Recently, two M-1 branch conotoxins (mr3e and tx3a) have been reported to possess a new disulfide bond arrangement between Cys1 and Cys5, Cys2 and Cys4, and Cys3 and Cys6, which is different from those seen in the M-2 and M-4 branches. Here we report the 3D structure of mr3e determined by 2D (1)H NMR in aqueous solution. Twenty converged structures of this peptide were obtained on the basis of 190 distance constraints obtained from NOE connectivities, as well as six varphi dihedral angle, three hydrogen bond, and three disulfide bond constraints. The rmsd values about the averaged coordinates of the backbone atoms were 0.43 +/- 0.19 A. Although mr3e has the same Cys arrangement as M-2 and M-4 conotoxins, it adopts a distinctive backbone conformation with the overall molecule resembling a 'flying bird'. Thus, different disulfide linkages may be employed by conotoxins with the same Cys framework to result in a more diversified backbone scaffold.

PubMed: 17437523
DOI: 10.1111/j.1742-4658.2007.05795.x

Experimental method

SOLUTION NMR