The replicon of pSW800 from Pantoea stewartii.
A 2019 bp DNA fragment containing the replicon of pSW800 from Pantoea stewartii SW2 was cloned and characterized. This replicon contains two genes--repA and repB, which encode a 36.5 kDa replication initiation protein (RepA) and a peptide of 18 aa, respectively. These two genes overlap by 8 bases with repB situated upstream. The replicon also transcribes an antisense RNA (RNAI) that inhibits the expression of repA and repB. The ribosome-binding sequence (RBS) of repA is likely to be hidden in a stem-loop structure, inhibiting the translation of repA. Furthermore, translation of repB is likely to disrupt the stem-loop structure, which is one of the criteria allowing the translation of repA to begin. A mutagenesis study revealed that a sequence (5'-GCACGGG-3') located 111 nt upstream from repA is crucial; mutation of this sequence prevented the translation of repA. Additionally, this region and the stem-loop structure containing the RBS of repA may form an RNA pseudoknot. Results in this study demonstrate that a mechanism similar to that regulating plasmid replication in the IncB, IncIalpha and IncL/M groups also regulates pSW800 replication.
Wu
Cheng-Yeu
CY
Department of Microbiology and Immunology, Chang-Gung University, Kwei-Shan, 333, Taiwan2.|Graduate Institute of Microbiology and Immunology, National Yang-Ming University, Shih-Pai, Taipei, 112, Taiwan1.
Fu
Jen-Fen
JF
Department of Microbiology and Immunology, Chang-Gung University, Kwei-Shan, 333, Taiwan2.
Liu
Shih-Tung
ST
Department of Microbiology and Immunology, Chang-Gung University, Kwei-Shan, 333, Taiwan2.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D004265:DNA Helicases; D004261:DNA Replication; D004268:DNA-Binding Proteins; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D020636:Pantoea / Q000235:genetics*; D010957:Plasmids / Q000235:genetics*; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D016372:RNA, Antisense; D034741:RNA, Small Interfering; D012093:Replicon / Q000235:genetics*; D017422:Sequence Analysis, DNA; D015534:Trans-Activators; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D011506:Proteins; D016372:RNA, Antisense; D034741:RNA, Small Interfering; C048817:RepB protein, Bacteria; D015534:Trans-Activators; C045264:replication initiator protein; D004265:DNA Helicases