1LSU

KTN Bsu222 Crystal Structure in Complex with NADH

Summary for 1LSU

• Entry DOI: 10.2210/pdb1lsu/pdb
• Related: 1LSS
• Descriptor: Conserved hypothetical protein yuaA, 1,4-DIHYDRONICOTINAMIDE ADENINE DINUCLEOTIDE (2 entities in total)
• Functional Keywords: ktn domain, nad, rck domain, potassium transport, potassium channel, ktra, rossmann fold, transport protein
• Biological source: Bacillus subtilis
• Cellular location: Cell membrane ; Peripheral membrane protein ; Cytoplasmic side : O32080
• Total number of polymer chains: 2
• Total formula weight: 33782.04

Authors

Roosild, T.P.,Miller, S.,Booth, I.R.,Choe, S. (deposition date: 2002-05-18, release date: 2002-07-03, Last modification date: 2024-02-14)

Primary citation

Roosild, T.P.,Miller, S.,Booth, I.R.,Choe, S.
A mechanism of regulating transmembrane potassium flux through a ligand-mediated conformational switch.
Cell(Cambridge,Mass.), 109:781-791, 2002

PubMed Abstract: 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.

PubMed: 12086676
DOI: 10.1016/S0092-8674(02)00768-7

Experimental method

X-RAY DIFFRACTION (2.85 Å)