Complete nucleotide sequence of human phosphoribosyl pyrophosphate synthetase subunit I (PRS I) cDNA and a comparison with human and rat PRPS gene families.
cDNA clones for human phosphoribosyl pyrophosphate synthetase subunit I (PRS I) were isolated from a glioblastoma cell line MGC 1 cDNA library. The longest clone contained 2,075 base pairs (bp) almost covering the 2.3-kb mRNA and the base sequence of the coding region (954 bp) had a 92.0% sequence homology with that of rat PRS I cDNA. The deduced amino acid sequences were identical between human and rat PRS I. This perfect conservation has heretofore not been reported for other enzymes involved in nucleotide metabolism and glycolysis. A comparison with other isoforms of this enzyme, PRS II and PRS III, showed that the human PRS I was 79.9 and 92.2% homologous in the coding sequence and 95.3 and 94.0% in the deduced amino acid sequence to human PRS II and PRS III, respectively. The high value of the synonymous difference between PRS I and PRS II cDNAs places their time of divergence long before that of the radiation of mammals. Based on the evolutionary rate of amino acid substitution, the PRS I and II genes probably diverged about 760 million years ago.
Sonoda
T
T
Department of Biochemistry, Chiba University School of Medicine.
Taira
M
M
Ishijima
S
S
Ishizuka
T
T
Iizasa
T
T
Tatibana
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D004247:DNA / Q000737:chemistry*; D015698:Genomic Library; D005910:Glioma / Q000201:enzymology*; D006801:Humans; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D005810:Multigene Family; D012333:RNA, Messenger / Q000737:chemistry; D051381:Rats; D015183:Restriction Mapping; D012268:Ribose-Phosphate Pyrophosphokinase / Q000235:genetics*; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D004247:DNA; D012268:Ribose-Phosphate Pyrophosphokinase