Cloning and cDNA sequence of the rat X-chromosome linked phosphoglycerate kinase

This paper reports the isolation and the sequence determination of rat phosphoglycerate kinase (PGK) cDNA clones. This cDNA, derived from an X-linked PGK gene transcript, contains a reading frame of 1254 nt and 5' and 3' non coding regions of 40 and 380 nt respectively. Analysis of the nucleotide sequence at the three codon position shows a biased codon usage with a prevalence of the triplet G non G N. Comparison of the inferred rat amino acid sequence with that of other organisms makes possible the calculation of the unit evolutionary period (UEP) for this enzyme, placing it at around 40 million years (My). Thus PGK is one of the oldest housekeeping enzymes.