title: Transcriptional analysis and functional characterization of XCC1294 gene encoding a GGDEF domain protein in Xanthomonas campestris pv. campestris.
abstract: The nucleotide cyclic di-GMP is a second messenger in bacteria that regulates a range of cellular functions including the virulence of pathogens. GGDEF is a protein domain involved in the synthesis of cyclic di-GMP. The genome of the crucifer pathogen Xanthomonas campestris pv. campestris (Xcc) encodes 21 proteins with a GGDEF domain. Clp, a homolog of the model transcription factor Crp of Escherichia coli, is a global regulator in Xcc. The aim of this study is to identify genes encoding GGDEF domain proteins whose expression is regulated by Clp. Results of reporter assay and RT-PCR analysis suggested that Clp regulates the expression of a set of genes encoding proteins harboring GGDEF domain. The transcription initiation site of XCC1294, one of the Clp regulated gene encoding a GGDEF domain protein, was mapped. Promoter analysis and gel retardation assay indicated that the transcription of XCC1294 is positively and directly regulated by Clp. Furthermore, transcription of XCC1294 was subject to catabolite repression and affected by several stress conditions. We also showed that mutation of XCC1294 results in enhanced surface attachment. In addition, transcription of three putative adhesin genes (xadA, fhaC, and yapH) was increased in the XCC1294 mutant. Taken together, the data presented here indicate that Clp positively regulates expression of XCC1294, and that XCC1294 serves a regulator of bacterial attachment and regulates different adhesin genes expression.
authors: Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan. ymhsiao@ctust.edu.tw
authors: Yi-Min
authors: YM
authors: Hsiao
authors: Wan-Ling
authors: WL
authors: Song
authors: Chao-Tsai
authors: CT
authors: Liao
authors: I-Hsuan
authors: IH
authors: Lin
authors: Mei-Ying
authors: MY
authors: Pan
authors: Ching-Fen
authors: CF
authors: Lin
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D001937:Brassica / Q000382:microbiology; D002874:Chromosome Mapping; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000378:metabolism*; D024363:Transcription Initiation Site; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*; D016959:Xanthomonas campestris / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; C436751:Clp protein, Xanthomonas campestris; D014157:Transcription Factors; D037521:Virulence Factors