The reversed terminator of octopine synthase gene on the Agrobacterium Ti plasmid has a weak promoter activity in prokaryotes.
Agrobacterium tumefaciens transfers DNA from its Ti plasmid to plant host cells. The genes located within the transferred DNA of Ti plasmid including the octopine synthase gene (OCS) are expressed in plant host cells. The 3'-flanking region of OCS gene, known as OCS terminator, is widely used as a transcriptional terminator of the transgenes in plant expression vectors. In this study, we found the reversed OCS terminator (3'-OCS-r) could drive expression of hygromycin phosphotransferase II gene (hpt II) and beta-glucuronidase gene in Escherichia coli, and expression of hpt II in A. tumefaciens. Furthermore, reverse transcription-polymerase chain reaction analysis revealed that an open reading frame (ORF12) that is located downstream to the 3'-OCS-r was transcribed in A. tumefaciens, which overlaps in reverse with the coding region of the OCS gene in octopine Ti plasmid.
Shao
Jun-Li
JL
Key Laboratory of Gene Engineering of the Ministry of Education and State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, China.
Long
Yue-Sheng
YS
Chen
Gu
G
Xie
Jun
J
Xu
Zeng-Fu
ZF
D016960:Agrobacterium tumefaciens / Q000201:enzymology* / Q000235:genetics*; D000594:Amino Acid Oxidoreductases / Q000235:genetics*; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D036741:Plant Tumor-Inducing Plasmids / Q000235:genetics*; D011387:Prokaryotic Cells / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011995:Recombination, Genetic / Q000235:genetics; D013728:Terminator Regions, Genetic; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
D000594:Amino Acid Oxidoreductases; C021903:D-octopine dehydrogenase