title: Identification of the σ⁷⁰-Dependent Promoter Controlling Expression of the ansPAB Operon of the Nitrogen-Fixing Bacterium Rhizobium etli.
abstract: The aim of the present work was to examine the putative promoter region of the operon ansPAB and to determine the general elements required for the regulation of transcriptional activity. The transcriptional start site of the ansPAB promoter was determined by using highresolution S1-nuclease mapping. Sequence analysis of this region showed -10 and -35 elements, which were consistent with consensus sequences for R. etli promoters that are recognized by the major form of RNA polymerase containing the σ(70) transcription factor. Mutation studies affecting several regions located upstream of the transcriptional start site confirmed the importance of these elements on transcriptional expression.
authors.affiliation: Escuela de Medicina, Universidad Marista de Mérida, Yucatán, México.
authors.forename: Angélica
authors.initials: A
authors.lastname: Moreno-Enríquez
authors.affiliation: Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco AC, Unidad Sureste, Parque Científico de Yucatán, Yucatán, México.
authors.forename: Zahaed
authors.initials: Z
authors.lastname: Evangelista-Martínez
authors.affiliation: Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, D.F., México.
authors.forename: Luis
authors.initials: L
authors.lastname: Servín-González
authors.affiliation: Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, D.F., México.
authors.forename: María Elena
authors.initials: ME
authors.lastname: Flores-Carrasco
mesh_terms: D004252:DNA Mutational Analysis; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D042163:Rhizobium etli / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012808:Sigma Factor / Q000378:metabolism*; D024363:Transcription Initiation Site
chemical_list: D012808:Sigma Factor; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases
keywords: Rhizobium etli; S1-nuclease mapping; asparagine operon; σ70 transcription factor