1fot
From Proteopedia
STRUCTURE OF THE UNLIGANDED CAMP-DEPENDENT PROTEIN KINASE CATALYTIC SUBUNIT FROM SACCHAROMYCES CEREVISIAE
Overview
The structure of TPK1delta, a truncated variant of the cAMP-dependent protein kinase catalytic subunit from Saccharomyces cerevisiae, was determined in an unliganded state at 2.8 A resolution and refined to a crystallographic R-factor of 19.4%. Comparison of this structure to that of its fully liganded mammalian homolog revealed a highly conserved protein fold comprised of two globular lobes. Within each lobe, root mean square deviations in Calpha positions averaged approximately equals 0.9 A. In addition, a phosphothreonine residue was found in the C-terminal domain of each enzyme. Further comparison of the two structures suggests that a trio of conformational changes accompanies ligand-binding. The first consists of a 14.7 degrees rigid-body rotation of one lobe relative to the other and results in closure of the active site cleft. The second affects only the glycine-rich nucleotide binding loop, which moves approximately equals 3 A to further close the active site and traps the nucleotide substrate. The third is localized to a C-terminal segment that makes direct contact with ligands and the ligand-binding cleft. In addition to resolving the conformation of unliganded enzyme, the model shows that the salient features of the cAMP-dependent protein kinase are conserved over long evolutionary distances.
About this Structure
1FOT is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
Structure of the unliganded cAMP-dependent protein kinase catalytic subunit from Saccharomyces cerevisiae., Mashhoon N, Carmel G, Pflugrath JW, Kuret J, Arch Biochem Biophys. 2001 Mar 1;387(1):11-9. PMID:11368172 Page seeded by OCA on Fri May 2 16:35:14 2008
