1T7E

Crystal structure of mutant Pro9Ser of scorpion alpha-like neurotoxin BmK M1 from Buthus martensii Karsch

1T7E の概要

• エントリーDOI: 10.2210/pdb1t7e/pdb
• 関連するPDBエントリー: 1sn1 1t7a 1t7b
• 分子名称: Alpha-like neurotoxin BmK-I, PHOSPHATE ION (3 entities in total)
• 機能のキーワード: bmk m1 mutant, scorpion toxin, buthus martensii karsch, toxin
• 由来する生物種: Mesobuthus martensii (Chinese scorpion)
• 細胞内の位置: Secreted: P45697
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 7711.33

構造登録者

Xiang, Y.,Guan, R.J.,He, X.L.,Wang, C.G.,Wang, M.,Zhang, Y.,Sundberg, E.J.,Wang, D.C. (登録日: 2004-05-09, 公開日: 2004-09-07, 最終更新日: 2024-12-25)

主引用文献

Guan, R.J.,Xiang, Y.,He, X.L.,Wang, C.G.,Wang, M.,Zhang, Y.,Sundberg, E.J.,Wang, D.C.
Structural Mechanism Governing Cis and Trans Isomeric States and an Intramolecular Switch for Cis/Trans Isomerization of a Non-proline Peptide Bond Observed in Crystal Structures of Scorpion Toxins
J.Mol.Biol., 341:1189-1204, 2004

PubMed Abstract: Non-proline cis peptide bonds have been observed in numerous protein crystal structures even though the energetic barrier to this conformation is significant and no non-prolyl-cis/trans-isomerase has been identified to date. While some external factors, such as metal binding or co-factor interaction, have been identified that appear to induce cis/trans isomerization of non-proline peptide bonds, the intrinsic structural basis for their existence and the mechanism governing cis/trans isomerization in proteins remains poorly understood. Here, we report the crystal structure of a newly isolated neurotoxin, the scorpion alpha-like toxin Buthus martensii Karsch (BmK) M7, at 1.4A resolution. BmK M7 crystallizes as a dimer in which the identical non-proline peptide bond between residues 9 and 10 exists either in the cis conformation or as a mixture of cis and trans conformations in either monomer. We also determined the crystal structures of several mutants of BmK M1, a representative scorpion alpha-like toxin that contains an identical non-proline cis peptide bond as that observed in BmK M7, in which residues within or neighboring the cis peptide bond were altered. Substitution of an aspartic acid residue for lysine at residue 8 in the BmK M1 (K8D) mutant converted the cis form of the non-proline peptide bond 9-10 into the trans form, revealing an intramolecular switch for cis-to-trans isomerization. Cis/trans interconversion of the switch residue at position 8 appears to be sequence-dependent as the peptide bond between residues 9 and 10 retains its wild-type cis conformation in the BmK M1 (K8Q) mutant structure. The structural interconversion of the isomeric states of the BmK M1 non-proline cis peptide bond may relate to the conversion of the scorpion alpha-toxins subgroups.

PubMed: 15321715
DOI: 10.1016/j.jmb.2004.06.067

実験手法

X-RAY DIFFRACTION (1.4 Å)