One amino acid change produces a high affinity cGMP-binding site in cAMP-dependent protein kinase.
Discrimination between cAMP and cGMP is a critical feature of cAMP- and cGMP-dependent protein kinases. An alanine/threonine difference in the cyclic nucleotide-binding sites has been proposed to provide a structural basis for this functional distinction. Site-directed mutagenesis of this alanine to a threonine in a cAMP-binding site of cAMP kinase produced a mutant with markedly increased cGMP affinity as determined by cGMP binding and protein kinase activation assays. Studies of other mutants at this position support the role of the threonine hydroxyl group as the component that enhances cGMP binding affinity.
Shabb
J B
JB
Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
Ng
L
L
Corbin
J D
JD
D000409:Alanine; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D013737:Testis / Q000201:enzymology; D013912:Threonine
D046911:Macromolecular Substances; D015345:Oligonucleotide Probes; D013912:Threonine; D000242:Cyclic AMP; D011494:Protein Kinases; D006152:Cyclic GMP; D000409:Alanine