Sequence of a cDNA for mouse thymidylate synthase reveals striking similarity with the prokaryotic enzyme.
We report the nucleotide sequence of a cloned cDNA, pMTS-3, that contains a 1-kb insert corresponding to mouse thymidylate synthase (E.C. 2.1.1.45). The open reading frame of 921 nucleotides from the first AUG to the termination codon specifies a protein with a molecular mass of 34,962 daltons. The predicted amino acid sequence is 90% identical with that of the human enzyme. The mouse sequence also has an extremely high degree of similarity (as much as 55% identity) with prokaryotic thymidylate synthase sequences, indicating that thymidylate synthase is among the most highly conserved proteins studied to date. The similarity is especially pronounced (as much as 80% identity) in the 44-amino-acid region encompassing the binding site for deoxyuridylic acid. The cDNA sequence also suggests that mouse thymidylate synthase mRNA lacks a 3' untranslated region, since the termination codon, UAA, is followed immediately by a poly(A) segment.
Perryman
S M
SM
Department of Biochemistry, Ohio State University, Columbus 43210.
Rossana
C
C
Deng
T L
TL
Vanin
E F
EF
Johnson
L F
LF
D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000235:genetics; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D005814:Genes, Viral; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D013940:Thymidylate Synthase / Q000235:genetics*
D004269:DNA, Bacterial; D012333:RNA, Messenger; D004247:DNA; D013940:Thymidylate Synthase