title: Distribution of putative xenogeneic silencers in prokaryote genomes.
abstract: Gene silencing is an important function as it keeps newly acquired foreign DNA repressed, thereby avoiding possible deleterious effects in the host organism. Known transcriptional regulators associated with this process are called xenogeneic silencers (XS) and belong to either the H-NS, Lsr2, MvaT or Rok families. In the work described here we looked for XS-like regulators and their distribution in prokaryotic organisms was evaluated. Our analysis showed that putative XS regulators similar to H-NS, Lsr2, MvaT or Rok are present only in bacteria (31.7%). This does not exclude the existence of alternative XS in the rest of the organisms analyzed. Additionally, of the four XS groups evaluated in this work, those from the H-NS family have diversified more than the other groups. In order to compare the distribution of these putative XS regulators we also searched for other nucleoid-associated proteins (NAPs) not included in this group such as Fis, EbfC/YbaB, HU/IHF and Alba. Results showed that NAPs from the Fis, EbfC/YbaB, HU/IHF and Alba families are widely (94%) distributed among prokaryotes. These NAPs were found in multiple combinations with or without XS-like proteins. In regard with XS regulators, results showed that only XS proteins from one family were found in those organisms containing them. This suggests specificity for this type of regulators and their corresponding genomes.
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología UNAM, Av. Universidad 2001, Cuernavaca, Morelos CP 62210, Mexico; Unidad Multidisciplinaria de Docencia e Investigación, Sisal Facultad de Ciencias, Sisal, Yucatán, UNAM, Mexico.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Perez-Rueda
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala. Col. Sto. Tomás, Distrito Federal, CP 11340, Mexico. Electronic address: jaig19@gmail.com.
authors.forename: J Antonio
authors.initials: JA
authors.lastname: Ibarra
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D022761:Gene Transfer, Horizontal / Q000235:genetics; D020745:Genome, Archaeal; D016680:Genome, Bacterial; D012097:Repressor Proteins / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C031908:H-NS protein, bacteria; D012097:Repressor Proteins
keywords: Archaea and Bacteria; Bacterial transcriptional regulators; Comparative genomics; Foreign DNA