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Random mutagenesis reveals a region important for gating of the yeast K + channel Ykc1
Author(s) -
Loukin Stephen H.,
Vaillant Brian,
Zhou XinLiang,
Spalding Edgar P.,
Kung Ching,
Saimi Yoshiro
Publication year - 1997
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/16.16.4817
Subject(s) - biology , mutagenesis , gating , genetics , yeast , saccharomyces cerevisiae , channel (broadcasting) , mutation , computational biology , gene , biophysics , engineering , electrical engineering
YKC1 ( TOK1 , DUK1 , YORK ) encodes the outwardly rectifying K + channel of the yeast plasma membrane. Non‐targeted mutations of YKC1 were isolated by their ability to completely block proliferation when expressed in yeast. All such mutations examined occurred near the cytoplasmic ends of the transmembrane segments following either of the duplicated P loops, which we termed the ‘post‐P loop’ (PP) regions. These PP mutations specifically caused marked defects in the ‘C 1 ’ states, a set of interrelated closed states that Ykc1 enters and exits at rates of tens to hundreds of milliseconds. These results indicate that the Ykc1 PP region plays a role in determining closed state conformations and that non‐targeted mutagenesis and microbial selection can be a valuable tool for probing structure–function relationships of ion channels.