title: The yrpAB operon of Yersinia ruckeri encoding two putative U32 peptidases is involved in virulence and induced under microaerobic conditions.
abstract: In an attempt to dissect the virulence mechanisms of Yersinia ruckeri two adjacent genes, yrpA and yrpB, encoding putative peptidases belonging to the U32 family, were analyzed. Similar genes, with the same genetic organization were identified in genomic analysis of human-pathogenic yersiniae. RT-PCR studies indicated that these genes form an operon in Y. ruckeri. Transcriptional studies using an yrpB::lacZY fusion showed high levels of expression of these genes in the presence of peptone in the culture medium, as well as under oxygen-limited conditions. These two factors had a synergic effect on gene induction when both were present simultaneously during bacterial incubation, which indicates the important role that environmental conditions in the fish gut can play in the regulation of specific genes. LD 50 experiments using an yrpA insertional mutant strain demonstrated the participation of this gene in the virulence of Y. ruckeri.
authors.affiliation: Área de Microbiología; Departamento de Biología Funcional; Facultad de Medicina; IUBA; Universidad de Oviedo; Oviedo, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Navais
authors.affiliation: Área de Microbiología; Departamento de Biología Funcional; Facultad de Medicina; IUBA; Universidad de Oviedo; Oviedo, Spain.
authors.forename: Jessica
authors.initials: J
authors.lastname: Méndez
authors.affiliation: Área de Microbiología; Departamento de Biología Funcional; Facultad de Medicina; IUBA; Universidad de Oviedo; Oviedo, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Pérez-Pascual
authors.affiliation: Área de Microbiología; Departamento de Biología Funcional; Facultad de Medicina; IUBA; Universidad de Oviedo; Oviedo, Spain.
authors.forename: Desirée
authors.initials: D
authors.lastname: Cascales
authors.affiliation: Área de Microbiología; Departamento de Biología Funcional; Facultad de Medicina; IUBA; Universidad de Oviedo; Oviedo, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Guijarro
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D000818:Animals; D019677:Artificial Gene Fusion; D005393:Fish Diseases / Q000382:microbiology* / Q000473:pathology; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D055786:Gene Knockout Techniques; D017930:Genes, Reporter; D007928:Lethal Dose 50; D016254:Mutagenesis, Insertional; D017686:Oncorhynchus mykiss; D009876:Operon; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*; D015009:Yersinia Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D044124:Yersinia ruckeri / Q000235:genetics* / Q000472:pathogenicity*; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
chemical_list: D037521:Virulence Factors; D001616:beta-Galactosidase; D010447:Peptide Hydrolases
keywords: Yersinia ruckeri; protease genes; regulation; virulence