skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Protein Kinase A Catalytic Subunit Primed for Action: Time-Lapse Crystallography of Michaelis Complex Formation

Abstract

The catalytic subunit of the cyclic AMP-dependent protein kinase A (PKAc) catalyzes the transfer of the γ-phosphate of bound Mg2ATP to a serine or threonine residue of a protein substrate. Here, time-lapse X-ray crystallography was used to capture a series of complexes of PKAc with an oligopeptide substrate and unreacted Mg2ATP, including the Michaelis complex, that reveal important geometric rearrangements in and near the active site preceding the phosphoryl transfer reaction. Contrary to the prevailing view, Mg2+ binds first to the M1 site as a complex with ATP and is followed by Mg2+ binding to the M2 site. Furthermore, the target serine hydroxyl of the peptide substrate rotates away from the active site toward the bulk solvent, which breaks the hydrogen bond with D166. In conclusion, the serine hydroxyl of the substrate rotates back toward D166 to form the Michaelis complex with the active site primed for phosphoryl transfer.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1334200
Alternate Identifier(s):
OSTI ID: 1235817; OSTI ID: 1250913
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Published Article
Journal Name:
Structure
Additional Journal Information:
Journal Name: Structure Journal Volume: 23 Journal Issue: 12; Journal ID: ISSN 0969-2126
Publisher:
Elsevier
Country of Publication:
United Kingdom
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Das, Amit, Gerlits, Oksana, Parks, Jerry M., Langan, Paul, Kovalevsky, Andrey, and Heller, William T. Protein Kinase A Catalytic Subunit Primed for Action: Time-Lapse Crystallography of Michaelis Complex Formation. United Kingdom: N. p., 2015. Web. doi:10.1016/j.str.2015.10.005.
Das, Amit, Gerlits, Oksana, Parks, Jerry M., Langan, Paul, Kovalevsky, Andrey, & Heller, William T. Protein Kinase A Catalytic Subunit Primed for Action: Time-Lapse Crystallography of Michaelis Complex Formation. United Kingdom. doi:10.1016/j.str.2015.10.005.
Das, Amit, Gerlits, Oksana, Parks, Jerry M., Langan, Paul, Kovalevsky, Andrey, and Heller, William T. Tue . "Protein Kinase A Catalytic Subunit Primed for Action: Time-Lapse Crystallography of Michaelis Complex Formation". United Kingdom. doi:10.1016/j.str.2015.10.005.
@article{osti_1334200,
title = {Protein Kinase A Catalytic Subunit Primed for Action: Time-Lapse Crystallography of Michaelis Complex Formation},
author = {Das, Amit and Gerlits, Oksana and Parks, Jerry M. and Langan, Paul and Kovalevsky, Andrey and Heller, William T.},
abstractNote = {The catalytic subunit of the cyclic AMP-dependent protein kinase A (PKAc) catalyzes the transfer of the γ-phosphate of bound Mg2ATP to a serine or threonine residue of a protein substrate. Here, time-lapse X-ray crystallography was used to capture a series of complexes of PKAc with an oligopeptide substrate and unreacted Mg2ATP, including the Michaelis complex, that reveal important geometric rearrangements in and near the active site preceding the phosphoryl transfer reaction. Contrary to the prevailing view, Mg2+ binds first to the M1 site as a complex with ATP and is followed by Mg2+ binding to the M2 site. Furthermore, the target serine hydroxyl of the peptide substrate rotates away from the active site toward the bulk solvent, which breaks the hydrogen bond with D166. In conclusion, the serine hydroxyl of the substrate rotates back toward D166 to form the Michaelis complex with the active site primed for phosphoryl transfer.},
doi = {10.1016/j.str.2015.10.005},
journal = {Structure},
number = 12,
volume = 23,
place = {United Kingdom},
year = {2015},
month = {12}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1016/j.str.2015.10.005

Save / Share: