Abstract:In this study, the fibrinolytic enzyme YG4 gene from marine Streptomyces sp. MY0504 was obtained and analyzed by bioinformatics methods. The genomic DNA of the extracted Streptomyces MY0504 was amplified by PCR using the degenerate primers designed based on the homologous sequences. The obtained DNA fragments were ligated to the pMD18-T vectors and transformed into competent Trans10 cells. The positive clones were then sequenced, and the obtained sequences were analyzed bioinformatically. Finally, the fibrinolytic enzyme YG4 gene from marine Streptomyces strain MY0504 sized 1083 bp was cloned. The obtained YG4 gene was introduced into the GenBank website, and then an alignment search and comparison was performed. The result showed that the YG4 gene exhibited 100% homology with the base sequence of the serine protease gene. The results of the 16s rDNA sequence analysis showed that the strain was closely related to Streptomyces daghestanicus, Streptomyces hydrogenans, Streptomyces albidoflavus and Streptomyces violascens. The primary structure, secondary structure, subcellular localization and tertiary structure of the protein encoded by YG4 gene were predicted and analyzed. The analysis results showed that the gene encoded 360 amino acids, and the encoded product was a stable hydrophilic protein. The secondary structure was mainly composed of alpha helix and beta sheet without signal peptides and transmembrane domains but with 40 phosphorylation sites. The high-order structure was dominated by random coils. The results of this study provided important information for investigating the expression mechanism of the fibrinolytic enzyme YG4 gene from marine Streptomyces MY0504 and for improving the expression level of a target protein.
