1LIR

LQ2 FROM LEIURUS QUINQUESTRIATUS, NMR, 22 STRUCTURES

Summary for 1LIR

• Entry DOI: 10.2210/pdb1lir/pdb
• Descriptor: LQ2 (1 entity in total)
• Functional Keywords: neurotoxin, scorpion, potassium channel blocker, inward rectifier potassium channel
• Biological source: Leiurus quinquestriatus hebraeus
• Total number of polymer chains: 1
• Total formula weight: 4350.02

Authors

Renisio, J.G.,Lu, Z.,Blanc, E.,Jin, W.,Lewis, J.H.,Bornet, O.,Darbon, H. (deposition date: 1998-04-02, release date: 1998-06-17, Last modification date: 2024-11-13)

Primary citation

Renisio, J.G.,Lu, Z.,Blanc, E.,Jin, W.,Lewis, J.H.,Bornet, O.,Darbon, H.
Solution structure of potassium channel-inhibiting scorpion toxin Lq2.
Proteins, 34:417-426, 1999

PubMed Abstract: Lq2 is a unique scorpion toxin. Acting from the extracellular side, Lq2 blocks the ion conduction pore in not only the voltage- and Ca2+ -activated channels, but also the inward-rectifier K+ channels. This finding argues that the three-dimensional structures of the pores in these K+ channels are similar. However, the amino acid sequences that form the external part of the pore are minimally conserved among the various classes of K+ channels. Because Lq2 can bind to all the three classes of K+ channels, we can use Lq2 as a structural probe to examine how the non-conserved pore-forming sequences are arranged in space to form similar pore structures. In the present study, we determined the three-dimensional structure of Lq2 using nuclear magnetic resonance (NMR) techniques. Lq2 consists of an alpha-helix (residues S10 to L20) and a beta-sheet, connected by an alphabeta3 loop (residues N22 to N24). The beta-sheet has two well-defined anti-parallel strands (residues G26 to M29 and residues K32 to C35), which are connected by a type I' beta-turn centered between residues N30 and K31. The N-terminal segment (residues Z1 to T8) appears to form a quasi-third strand of the beta-sheet.

PubMed: 10081954
DOI: 10.1002/(SICI)1097-0134(19990301)34:4<417::AID-PROT1>3.3.CO;2-I

Experimental method

SOLUTION NMR