Xi Tree Sls Separation Of Candidate Genes And Functional Predictions

Camptothecin is an antitumor drug, many genes are involved in Camptothecin biosynthetic pathway. In the present study, DNA and RNA, which were used as PCR templates, were extracted from young leaves of Camptothecia acuminate, respectively. Degenerate primers were designed according to the conserved sequence of CYP450 72A(Secologanin synthase, SLS)from Catharanthus roseus. The partial fragment of sls-like gene was amplified from C. acuminate, and then the unknown flanking sequences of known fragment were amplified by chromosome walking. A sequence assembly was produced from these amplified fragments, sequenced, and used in the design of primers for RT-PCR. Our results show that the full-length cDNA sequence of sls-like gene from C. acuminate was successfully cloned. The full-length cDNA sequence of sls-like has 1706 bp and contains an open reading frame (ORF) of 1575 bp which encodes a peptide of 524 amino acids. Furthermore, the bioinformatic analysis suggests that (1) the relative molecular weight of the protein is about 59.8 kDa. (2) its isoelectric point is 8.92 with hydrophilic characteristics. (3) it contains signal peptide and transmembrane domain. (4) it is probably located in endoplasmic reticulum membrane. (5) its secondary structure is mainly composed of random coil and alpha helix. (6) The phylogenetic tree shows that the sls-like is the closest homolog of C. roseus SLS.