Structural similarities between glutamate receptor channels and K(+) channels examined by scanning mutagenesis.

ABSTRACT: The pores of glutamate receptors and K(+) channels share sequence homology, suggesting a conserved secondary structure. Scanning mutagenesis with substitution of alanine and tryptophan in GluR6 channels was performed based on the structure of KcsA. Our assay used disruption of voltage-dependent polyamine block to test for changes in the packing of pore-forming regions. Alanine scanning from D567 to R603 revealed reduced rectification resulting from channel block in two regions. A periodic pattern from F575 to M589 aligned with the pore helix in KcsA, whereas a cluster of sensitive positions around Q590, a site regulated by RNA editing, mapped to the selectivity filter in KcsA. Tryptophan scanning from D567 to R603 revealed similar patterns, but with a complete disruption of spermine block

SUBMITTER: Panchenko VA 

PROVIDER: S-EPMC2217257 | biostudies-literature | 2001 Apr

REPOSITORIES: biostudies-literature