We apologize for Proteopedia being slow to respond. For the past two years, a new implementation of Proteopedia has been being built. Soon, it will replace this 18-year old system. All existing content will be moved to the new system at a date that will be announced here.

4iak

From Proteopedia

Jump to: navigation, search

Low temperature X-ray structure of cAMP dependent protein kinase A in complex with high Sr2+ concentration, ADP and phosphorylated peptide pSP20

Structural highlights

4iak is a 2 chain structure with sequence from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.6Å
Ligands:	, , , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

IPKA_HUMAN Extremely potent competitive inhibitor of cAMP-dependent protein kinase activity, this protein interacts with the catalytic subunit of the enzyme after the cAMP-induced dissociation of its regulatory chains.

Publication Abstract from PubMed

X-ray structures of several ternary substrate and product complexes of the catalytic subunit of cAMP-dependent protein kinase (PKAc) have been determined with different bound metal ions. In the PKAc complexes, Mg2+, Ca2+, Sr2+, and Ba2+ metal ions could bind to the active site and facilitate the phosphoryl transfer reaction. ATP and a substrate peptide (SP20) were modified, and the reaction products ADP and the phosphorylated peptide were found trapped in the enzyme active site. Finally, we determined the structure of a pseudo-Michaelis complex containing Mg2+, nonhydrolyzable AMP-PCP (beta,gamma-methyleneadenosine 5'-triphosphate) and SP20. The product structures together with the pseudo-Michaelis complex provide snapshots of different stages of the phosphorylation reaction. Comparison of these structures reveals conformational, coordination, and hydrogen bonding changes that might occur during the reaction and shed new light on its mechanism, roles of metals, and active site residues.

Insights into the Phosphoryl Transfer Catalyzed by cAMP-Dependent Protein Kinase: An X-ray Crystallographic Study of Complexes with Various Metals and Peptide Substrate SP20.,Gerlits O, Waltman MJ, Taylor S, Langan P, Kovalevsky A Biochemistry. 2013 May 14. PMID:23672593^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Gerlits O, Waltman MJ, Taylor S, Langan P, Kovalevsky A. Insights into the Phosphoryl Transfer Catalyzed by cAMP-Dependent Protein Kinase: An X-ray Crystallographic Study of Complexes with Various Metals and Peptide Substrate SP20. Biochemistry. 2013 May 14. PMID:23672593 doi:10.1021/bi400066a