Nucleotide sequence of a functional cDNA for human thymidylate synthase

Area of Science:

• Molecular Biology
• Biochemistry
• Genetics

Background:

• Thymidylate synthase (TS) is a crucial enzyme in DNA synthesis.
• Understanding human TS at the molecular level is important for drug development and cancer research.

Purpose of the Study:

• To determine the nucleotide sequence of the human thymidylate synthase (TS) cDNA clone pcHTS-1.
• To analyze the predicted amino acid sequence and identify conserved regions.
• To investigate the 5'-untranslated region for potential regulatory elements.

Main Methods:

• Nucleotide sequencing of the cDNA clone pcHTS-1.
• Bioinformatic analysis of the predicted amino acid sequence.
• Comparison of the human TS sequence with homologous sequences from other organisms.
• Analysis of secondary structure formation in the 5'-untranslated region.

Main Results:

• The 1.6 kilobase cDNA insert encodes a 313 amino acid subunit protein (Mr = 35,706).
• The predicted amino acid sequence shows high conservation in critical regions, including substrate and inhibitor binding sites, when compared to bacterial and viral TS.
• A unique 90-nucleotide triple tandem repeat sequence with high G+C content (80%) was identified in the 5'-untranslated region, capable of forming stem-loop structures.

Conclusions:

• The determined nucleotide sequence provides a complete genetic blueprint for human thymidylate synthase.
• Conserved regions suggest functional importance and evolutionary relatedness of TS across species.
• The novel 5'-untranslated region structure may play a role in the regulation of human TS expression.