1lsu
From Proteopedia
KTN Bsu222 Crystal Structure in Complex with NADH
Overview
The regulation of cation content is critical for cell growth. However, the molecular mechanisms that gate the systems that control K+ movements remain unclear. KTN is a highly conserved cytoplasmic domain present ubiquitously in a variety of prokaryotic and eukaryotic K+ channels and transporters. Here we report crystal structures for two representative KTN domains that reveal a dimeric hinged assembly. Alternative ligands NAD+ and NADH block or vacate, respectively, the hinge region affecting the dimer's conformational flexibility. Conserved, surface-exposed hydrophobic patches that become coplanar upon hinge closure provide an assembly interface for KTN tetramerization. Mutational analysis using the KefC system demonstrates that this domain directly interacts with its respective transmembrane constituent, coupling ligand-mediated KTN conformational changes to the permease's activity.
About this Structure
1LSU is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
A mechanism of regulating transmembrane potassium flux through a ligand-mediated conformational switch., Roosild TP, Miller S, Booth IR, Choe S, Cell. 2002 Jun 14;109(6):781-91. PMID:12086676 Page seeded by OCA on Sat May 3 00:15:12 2008
