title: Functional analysis of the aefR mutation and identification of its binding site in Pseudomonas syringae pv. tabaci 11528.
abstract: The TetR family transcriptional regulator AefR contributes to the regulation of the quorum-sensing system. However, the role of AefR in the regulatory network of the phytopathogen Pseudomonas syringae pathovars is not known. In this study, the phenotype of a P. syringae pv. tabaci 11528 aefR deletion mutant strain was examined. The aefR gene expression and AefR DNA-binding affinity were examined by quantitative real-time polymerase chain reaction and electrophoretic mobility shift assay, respectively. AefR was found to control quorum-sensing genes as well as the efflux genes mexE, mexF, and oprN via an indirect mechanism. AefR binds to its own operator site as well as to the palindromic sequence between positions -28 and -2 corresponding to the transcription start site of aefR, as determined by dye primer sequencing. These results suggest that P. syringae AefR modulates quorum sensing and efflux as well as its own expression, which can be exploited by strategies developed to manage this plant parasite.
authors.affiliation: Department of Integrated Biological Science, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Sora
authors.initials: S
authors.lastname: Yun
authors.affiliation: Department of Integrated Biological Science, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Jun Seung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Integrated Biological Science, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Mi Sol
authors.initials: MS
authors.lastname: Do
authors.affiliation: Department of Integrated Biological Science, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Young Ji
authors.initials: YJ
authors.lastname: Jeon
authors.affiliation: Department of Biotechnology and Bioengineering, College of Engineering, Dong-Eui University, Busan 614-714, Republic of Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Cha
authors.affiliation: Department of Integrated Biological Science, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea hsubaik@pusan.ac.kr.
authors.forename: Hyung Suk
authors.initials: HS
authors.lastname: Baik
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D009154:Mutation; D044224:Pseudomonas syringae / Q000235:genetics* / Q000378:metabolism*; D053038:Quorum Sensing; D060888:Real-Time Polymerase Chain Reaction; D050436:Regulatory Elements, Transcriptional
chemical_list: D001426:Bacterial Proteins
keywords: AefR; dye primer sequencing; electrophoretic mobility shift assay; quorum sensing