Characterization of amino acid substitutions in KdpA, the K+-binding and -translocating subunit of the KdpFABC complex of Escherichia coli.
When grown under K+ limitation, Escherichia coli induces the K+-translocating KdpFABC complex. The stimulation of ATPase activity by NH4+ ions was shown for the first time. Substitutions in KdpA, which is responsible for K+ binding and translocation, revealed that enzyme complexes KdpA:G232A and KdpA:G232S have completely lost their cation selectivity.
van der Laan
Martin
M
Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, D-49069 Osnabrück, Germany.
Gassel
Michael
M
Altendorf
Karlheinz
K
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019943:Amino Acid Substitution; D027682:Cation Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002412:Cations / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005998:Glycine; D016297:Mutagenesis, Site-Directed; D010957:Plasmids / Q000235:genetics; D011188:Potassium / Q000378:metabolism
D027682:Cation Transport Proteins; D002412:Cations; D029968:Escherichia coli Proteins; D000251:Adenosine Triphosphatases; C058166:potassium translocating Kdp-ATPase, E coli; D011188:Potassium; D005998:Glycine