Mu-Like Prophage Strong Gyrase Site Sequences: Analysis of Properties Required for Promoting Efficient Mu DNA Replication
AUTOR(ES)
Oram, Mark
FONTE
American Society for Microbiology
RESUMO
The bacteriophage Mu genome contains a centrally located strong gyrase site (SGS) that is required for efficient prophage replication. To aid in studying the unusual properties of the SGS, we sought other gyrase sites that might be able to substitute for the SGS in Mu replication. Five candidate sites were obtained by PCR from Mu-like prophage sequences present in Escherichia coli O157:H7 Sakai, Haemophilus influenzae Rd, Salmonella enterica serovar Typhi CT18, and two strains of Neisseria meningitidis. Each of the sites was used to replace the natural Mu SGS to form recombinant prophages, and the effects on Mu replication and host lysis were determined. The site from the E. coli prophage supported markedly enhanced replication and host lysis over that observed with a Mu derivative lacking the SGS, those from the N. meningitidis prophages allowed a small enhancement, and the sites from the Haemophilus and Salmonella prophages gave none. Each of the candidate sites was cleaved specifically by E. coli DNA gyrase both in vitro and in vivo. Supercoiling assays performed in vitro, with the five sites or the Mu SGS individually cloned into a pUC19 reporter plasmid, showed that the Mu SGS and the E. coli or N. meningitidis sequences allowed an enhancement of processive, gyrase-dependent supercoiling, whereas the H. influenzae or Salmonella serovar Typhi sequences did not. While consistent with a requirement for enhanced processivity of supercoiling for a site to function in Mu replication, these data suggest that other factors are also important. The relevance of these observations to an understanding of the function of the SGS is discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=438558Documentos Relacionados
- Mu-Like Prophage in Serogroup B Neisseria meningitidis Coding for Surface-Exposed Antigens
- Genetic characterization of Mu-like bacteriophage D108.
- Replacement of the Bacteriophage Mu Strong Gyrase Site and Effect on Mu DNA Replication
- Characterization of Mu prophage lacking the central strong gyrase binding site: localization of the block in replication.
- In vitro maturation and encapsidation of the DNA of transposable Mu-like phage D108.