Abstract:Cis-prenyltransferases is the key enzyme to rubber biosynthesis. A cDNA fragment which was highly homologous to the gene encoding cis-prenyltransferases was isolated by screening of a latex subtracted cDNA library. The latex subtracted cDNA library was constructed by suppressive subtractive hybridization (SSH), in which the polyA+RNA of latex from Hevea brasiliensis served as tester, and polyA+RNA of leaves as driver. According to its sequences information, a novel full-length cDNA of 1 156 bp termed R363 (GenBank number: AY461414) was obtained by using rapid amplification of cDNA ends (RACE). R363 contained a 1 035 bp ORF, which encoded 290 amino acids with a theoretical molecular weight of 32.9 kD and an isoelectric point of 7.2. Hydropathy and transmembrane motif analysis of deduced amino acid sequences indicated that R363 possessed a signal peptide of 27 amino acids at its N-end. The result of the conserved domains analysis indicated that R363 contained five highly conserved regions as well as signature motif of undecaprenyl pyrophosphate sythetase family, which implied that R363 would be a cis-prenyltransferases gene. Furthermore, the transcripts of R363 were expressed predominantly in the latex as compared with leaves, and exerted no differences in latex with or without 2% ethylene pretreatment.
