Int J Biochem Mol Biol 2011;2(2):111-118

Original Article
A new crystal form of mouse thiamin pyrophosphokinase

Jing-Yuan Liu, Thomas D. Hurley

Departments of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.

Received February 22, 2011; accepted February 26, 2011; Epub February 28, 2011; Published published April 30, 2011

Abstract: Thiamin pyrophosphokinase (TPK) transfers a pyrophosphate group from ATP to the hydroxyl group of thiamin and produces thiamin
pyrophosphate (TPP).  TPP is the cofactor of metabolically important enzymes such as pyruvate dehydrogenase, α-ketoglutarate
dehydrogenase, branched-chain α-keto acid dehydrogenase, transketolase and 2-hydroxyphytanoyl-CoA lyase.  Thiamin deficiency results in
Wernike-Korsakof Syndrome (WKS) due to neurological disorder and wet beriberi, a potentially fatal cardiovascular.  Mouse TPK associates as
a dimer revealed by previous solved crystallographic structures.  In this study, we report mouse TPK complexed with TPP-Mg2+ and thiamin-
Mg2+, respectively, in a new crystal form. In these two structures, four mouse TPK molecules were found in each asymmetric unit. Although we
cannot rule out this tetramer form can be an artifact from crystal packing, mouse TPK tetramer has a more closed ATP binding pocket  and has
the potential to provide specific interactions between mouse TPK and ATP compared with the previous dimeric structure and is likely to be an
active form. (IJBMB1102003).

Keywords: Thiamin pyrophosphokinase (TPK), crystal structure, TPP-Mg2+, thiamin-Mg2+, mouse

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Address all correspondence to:
Dr. Jing-Yuan Liu
Departments of Biochemistry and Molecular Biology
Indiana University School of Medicine
Indianapolis, IN 46202
Tel (317) 274-7645; Fax (317) 274-7714