Pa. Ropp et Tw. Traut, CLONING AND EXPRESSION OF A CDNA-ENCODING URIDINE KINASE FROM MOUSE-BRAIN, Archives of biochemistry and biophysics, 336(1), 1996, pp. 105-112
Uridine kinase is the rate-limiting enzyme in the pyrimidine salvage p
athway of all mammalian cells. A cDNA for uridine kinase from mouse br
ain has been isolated, sequenced, and characterized. This is the first
report of a complete nucleotide sequence for mammalian uridine kinase
. The isolated cDNA is only 95% complete, missing the first 17 codons.
The correct 5'-terminus sequence was obtained from high-stringency sc
reening of a mouse liver genomic DNA library. The translated cDNA sequ
ence encodes a protein of 277 amino acids (M(r) 31,068). A truncated f
orm of the cDNA was expressed in Escherichia coli. The expressed prote
in displayed uridine kinase activity and readily formed a tetramer, th
e most active form of the wildtype enzyme. Analysis of the amino acid
sequence identified the three ATP-binding site consensus motifs. The p
redicted secondary structure for uridine kinase and the sequence compa
rison with three kinases having known crystal structures are consisten
t with uridine kinase having an alpha/beta core structure of the nucle
otide-binding fold found in many kinases. We have also isolated and cl
oned a nonfunctional, processed pseudogene from mouse genomic DNA. Thi
s pseudogene sequence is 94% identical with the coding DNA. (C) 1996 A
cademic Press, Inc.