Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Sci. Signal., 2 March 2010
Vol. 3, Issue 111, p. ra17
[DOI: 10.1126/scisignal.2000525]

RESEARCH ARTICLES

Crystal Structure of the {alpha}-Kinase Domain of Dictyostelium Myosin Heavy Chain Kinase A

Qilu Ye*, Scott W. Crawley*, Yidai Yang, Graham P. Côté{dagger}, and Zongchao Jia

Department of Biochemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6.

* These authors contributed equally to this work.

Abstract: Dictyostelium discoideum myosin II heavy chain kinase A (MHCK A) disrupts the assembly and cellular activity of bipolar filaments of myosin II by phosphorylating sites within its {alpha}-helical, coiled-coil tail. MHCK A is a member of the atypical {alpha}-kinase family of serine and threonine protein kinases and displays no sequence homology to typical eukaryotic protein kinases. We report the crystal structure of the {alpha}-kinase domain (A-CAT) of MHCK A. When crystallized in the presence of adenosine triphosphate (ATP), A-CAT contained adenosine monophosphate (AMP) at the active site. However, when crystallized in the presence of ATP and a peptide substrate, which does not appear in the structure, adenosine diphosphate (ADP) was found at the active site and an invariant aspartic acid residue (Asp766) at the active site was phosphorylated. The aspartylphosphate group was exposed to the solvent within an active-site pocket that might function as a docking site for substrates. Access to the aspartylphosphate was regulated by a conformational switch in a loop that bound to a magnesium ion (Mg2+), providing a mechanism that allows {alpha}-kinases to sense and respond to local changes in Mg2+.

{dagger} To whom correspondence should be addressed. E-mail: coteg{at}queensu.ca

Citation: Q. Ye, S. W. Crawley, Y. Yang, G. P. Côté, Z. Jia, Crystal Structure of the {alpha}-Kinase Domain of Dictyostelium Myosin Heavy Chain Kinase A. Sci. Signal. 3, ra17 (2010).

Read the Full Text

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Autophosphorylation Activates Dictyostelium Myosin II Heavy Chain Kinase A by Providing a Ligand for an Allosteric Binding Site in the {alpha}-Kinase Domain.
S. W. Crawley, M. S. Gharaei, Q. Ye, Y. Yang, B. Raveh, N. London, O. Schueler-Furman, Z. Jia, and G. P. Cote (2011)
J. Biol. Chem. 286, 2607-2616
   Abstract »    Full Text »    PDF »
Science Signaling Podcast: 4 January 2011.
M. B. Yaffe and A. M. VanHook (2011)
Science Signaling 4, pc1
   Abstract »    Full Text »

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882