Parathymosin (PTMS)

Parathymosin is a polypeptide similar in size and amino acid composition to prothymosin-alpha. It has a high content of dicarboxylic amino acids and a complete absence of aromatic and sulfur-containing amino acids. It has 101 amino acid residues as compared to 111 for prothymosin. Clinton et al. (1989) reported the isolation of a cDNA clone for human kidney parathymosin containing the complete coding region and extending into the 5-prime and 3-prime flanking sequences. The open reading frame contains 306 nucleotides, including the codon for the initiator methionine. Analysis of the 5-prime flanking sequence excluded the presence of a hydrophobic signal peptide in the translated sequence. This permitted the conclusion that parathymosin, like prothymosin-alpha, is synthesized without formation of a larger precursor polypeptide.