cDNA, genomic sequence cloning, analyzing of ribosomal protein L19 from Ailuropoda melanoleuca and its overexpression

RPL19 is a component of 60S large ribosomal subunit encoded by the RPL19 gene. To explore the structure feature of RPL19 gene of the Ailuropoda melanoleuca, the cDNA and genomic sequence of RPL19 gene were cloned using RT-PCR and touchdown-PCR technology. The result revealed that the length of cDNA fragment cloned was 642bp containing an open-reading frame of 591bp, encoding 196 amino acids with an estimated protein molecular weight 23.46kD and a theoretical pI of 12.01. The genomic sequence was 4309 bp in length with six exons and five introns. Alignment analysis indicated that the CDS showed very high homologious with other reported species, and the deduced amino acid sequence of RPL19 gene was the same with them. The predicted protein had five different patterns of functional sites. The RPL19 gene could be readily expressed in E. coli. When it was fused with the N-terminally His-tagged protein, it gave rise to accumulation of an expected 29kD polypeptide, in good agreement with the predicted molecular weight. The expression product obtained can be purified for studies of its function. The cDNA of RPL19 was cloned successfully for the first time from the Ailuropoda melanoleuca in this research. The results provided scientific material to enrich and improve the RPL19 gene database.