Gene cloning of squalene synthase in Alisma orientalis and its bioinformatic analysis / 中草药

ABSTRACT

Objective: To clone the full-length cDNA encoding squalene synthase (SS), a key enzyme of protostane type triterpenes biosynthesis, from Alisma orientalis and to perform bioinformatic analysis. Methods: With the total RNA as template, the full-length cDNA of SS in A. orientalis was cloned via homology-based cloning approach and rapid amplification of cDNA ends technique. The bioinformatics of the cloning SS gene was analyzed by DNAMAN and ExPASy online analysis. Results: The full-length cDNA (1 577 bp) of SS gene was obtained (GenBank accession number JX866770), with an open reading frame of 1 230 bp, encoding 409 amino acid polypeptides, which had higher homology with the known SS in other medicinal species. The calculated relative molecular mass was 4.68 × 104, the isoelectric point was 5.97, and there was no signal peptide in SS. The deduced protein sequence exhibited two conserved domains rich in Asp (DXXDD). Conclusion: The cDNA encoding SS from A. orientalis is cloned and reported for the first time. This work provides a foundation for exploring the biosynthetic pathway of protostane type triterpenes in A. orientalis and their applications in bioengineering.