Serotype 1a O-Antigen Modification: Molecular Characterization of the Genes Involved and Their Novel Organization in the Shigella flexneri Chromosome
AUTOR(ES)
Adhikari, Pradip
FONTE
American Society for Microbiology
RESUMO
The factors responsible for serotype 1a O-antigen modification in Shigella flexneri were localized to a 5.8-kb chromosomal HindIII fragment of serotype 1a strain Y53. The entire 5.8-kb fragment and regions up- and downstream of it (10.6-kb total) were sequenced. A putative three-gene operon, which showed homology with other serotype conversion genes, was identified and shown to confer serotype 1a O-antigen modification. The serotype conversion genes were flanked on either side by phage DNA. Multiple insertion sequence (IS) elements were located within and upstream of the phage DNA in a composite transposon-like structure. Host DNA homologous to the dsdC and the thrW proA genes was located upstream of the IS elements and downstream of the phage DNA, respectively. The sequence analysis indicates that the organization of the 10.6-kb region of the Y53 chromosome is unique and suggests that the serotype conversion genes were originally brought into the host by a bacteriophage. Several features of this region are also characteristic of pathogenicity islands.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=103612Documentos Relacionados
- Molecular, genetic, and topological characterization of O-antigen chain length regulation in Shigella flexneri.
- Novel Aeromonas hydrophila PPD134/91 Genes Involved in O-Antigen and Capsule Biosynthesis
- Novel Aeromonas hydrophila PPD134/91 Genes Involved in O-Antigen and Capsule Biosynthesis
- Escherichia coli Clone Sonnei (Shigella sonnei) Had a Chromosomal O-Antigen Gene Cluster Prior to Gaining Its Current Plasmid-Borne O-Antigen Genes
- O-antigen specificities of the serotype strains of Serratia marcescens.