title: AvrXa27 binding influences unwinding of the double-stranded DNA in the UPT box.
abstract: Transcription-Activator Like (TAL) effectors, delivered by Xanthomonas pathogens bind specifically to UP-regulated by TAL effectors (UPT) box of the host gene promoter to arouse disease or trigger defense response. This type of protein-DNA interaction model has been applied in site-directed genome editing. However, the off-target effects of TAL have severely hindered the development of this promising technology. To better exploit the specific interaction and to deeper understand the TAL-induced host transcription rewiring, the binding between the central repeat region (CRR) of the TAL effector AvrXa27 and its UPT box variants was studied by kinetics analysis and TAL-blocked helicase unwinding assay. The results revealed that while AvrXa27 exhibited the highest affinity to the wild type UPT box, it could also bind to mutated UPT box variants, implying the possibility of non-specific interactions. Furthermore, some of these non-specific combinations restricted the helicase-elicited double-stranded DNA (dsDNA) separation to a greater extent. Our findings provide insight into the mechanism of TAL transcriptional activation and are beneficial to TAL-mediated genome modification.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
authors.forename: Junpeng
authors.initials: J
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
authors.forename: Nanv
authors.initials: N
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.
authors.forename: Xuguang
authors.initials: X
authors.lastname: Xi
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, People's Republic of China. Electronic address: jingfu@nwsuaf.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Fu
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D014974:Xanthomonas / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004247:DNA
keywords: Binding affinity; Helicase; TAL; Transcriptional activation