title: Molecular Analysis of Promoter and Intergenic Region Attenuator of the Vibrio vulnificus prx1ahpF Operon.
abstract: Prx1, an AhpF-dependent 2-Cys peroxiredoxin (Prx), was previously identified in Vibrio vulnificus, a facultative aerobic pathogen. In the present study, transcription of the V. vulnificus prx1ahpF genes, which are adjacently located on the chromosome, was evaluated by analyzing the promoter and intergenic region of the two genes. Northern blot analyses revealed that transcription of prx1ahpF results in two transcripts, the prx1 and prx1ahpF transcripts. Primer extension analysis and a point mutational analysis of the promoter region showed that the two transcripts are generated from a single promoter. In addition, the 3' end of the prx1 transcript at the prx1ahpF intergenic region was determined by a 3'RACE assay. These results suggested that the prx1ahpF genes are transcribed as an operon, and the prx1 transcript was produced by transcriptional termination in the intergenic region. RNA secondary structure prediction of the prx1ahpF intergenic region singled out a stem-loop structure without poly(U) tract, and a deletion analysis of the intergenic region showed that the atypical stem-loop structure acts as the transcriptional attenuator to result in the prx1 and prx1ahpF transcripts. The combined results demonstrate that the differential expression of prx1 and ahpF is accomplished by the cis-acting transcriptional attenuator located between the two genes and thereby leads to the production of a high level of Prx1 and a low level of AhpF.
authors.affiliation: Korea Food Research Institute, Seongnam 463-746, Republic of Korea.
authors.forename: Hyun Sung
authors.initials: HS
authors.lastname: Lee
authors.affiliation: National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Jong Gyu
authors.initials: JG
authors.lastname: Lim
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors.forename: Kook
authors.initials: K
authors.lastname: Han
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
authors.forename: Younghoon
authors.initials: Y
authors.lastname: Lee
authors.affiliation: National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Choi
mesh_terms: D015152:Blotting, Northern; D004252:DNA Mutational Analysis; D021901:DNA, Intergenic; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D009690:Nucleic Acid Conformation; D009876:Operon; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D024363:Transcription Initiation Site; D061806:Transcription Termination, Genetic; D041261:Vibrio vulnificus / Q000235:genetics*
chemical_list: D021901:DNA, Intergenic; D012333:RNA, Messenger
keywords: Vibrio vulnificus; alkyl hydroperoxide reductase; peroxiredoxin; transcriptional attenuation