A mutation in the catalytic subunit of cAMP-dependent protein kinase that disrupts regulation Academic Article uri icon


MeSH Major

  • Cyclic AMP
  • Protein Kinases
  • Saccharomyces cerevisiae


  • A mutant catalytic subunit of adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase has been isolated from Saccharomyces cerevisiae that is no longer subject to regulation yet retains its catalytic activity. Biochemical analysis of the mutant subunit indicates a 100-fold decreased affinity for the regulatory subunit. The mutant catalytic subunit exhibits approximately a threefold increase in Michaelis constant for adenosine triphosphate and peptide cosubstrates, and is essentially unchanged in its catalytic rate. The nucleotide sequence of the mutant gene contains a single nucleotide change resulting in a threonine-to-alanine substitution at amino acid 241. This residue is conserved in other serine-threonine protein kinases. These results identify this threonine as an important contact between catalytic and regulatory subunits but only a minor contact in substrate recognition.

publication date

  • December 1988



  • Academic Article



  • eng

PubMed ID

  • 2832943

Additional Document Info

start page

  • 68

end page

  • 70


  • 240


  • 4848