2.2 A refined crystal structure of the catalytic subunit of cAMP-dependent protein kinase complexed with MnATP and a peptide inhibitor.Zheng, J., Trafny, E.A., Knighton, D.R., Xuong, N.H., Taylor, S.S., Ten Eyck, L.F., Sowadski, J.M.
(1993) Acta Crystallogr D Biol Crystallogr 49: 362-365
- PubMed: 15299527
- DOI: https://doi.org/10.1107/S0907444993000423
- Primary Citation of Related Structures:
- PubMed Abstract:
. The crystal structure of a ternary complex containing the catalytic subunit of cAMP-dependent protein kinase, ATP and a 20-residue inhibitor peptide was refined at a resolution of 2.2 A to an R value of 0.177. In order to identify the metal binding sites, the crystals, originally grown in the presence of low concentrations of Mg(2+), were soaked in Mn(2+). Two Mn(2+) ions were identified using an anomalous Fourier map. One Mn(2+) ion bridges the gamma- and beta-phosphates and interacts with Asp184 and two water molecules. The second Mn(2+) ion interacts with the side chains of Asn171 and Asp l84 as well as with a water molecule. Modeling a serine into the P site of the inhibitor peptide suggests a mechanism for phosphotransfer.
Department of Chemistry, University of California, San Diego, La Jolla 92093-0654, USA.