title: A previously uncharacterized tetratricopeptide-repeat-containing protein is involved in cell envelope function in Rhizobium leguminosarum.
abstract: Rhizobium leguminosarum is a soil bacterium that is an intracellular symbiont of leguminous plants through the formation of nitrogen-fixing root nodules. Due to the changing environments that rhizobia encounter, the cell is often faced with a variety of cell altering stressors that can compromise the cell envelope integrity. A previously uncharacterized operon (RL3499-RL3502) has been linked to proper cell envelope function, and mutants display pleiotropic phenotypes including an inability to grow on peptide-rich media. In order to identify functional partners to the operon, suppressor mutants capable of growth on complex, peptide-rich media were isolated. A suppressor mutant of a non-polar mutation to RL3500 was chosen for further characterization. Transposon mutagenesis, screening for loss of the suppressor phenotype, led to the identification of a Tn5 insertion in an uncharacterized tetratricopeptide-repeat-containing protein RL0936. Furthermore, RL0936 had a 3.5-fold increase in gene expression in the suppressor strain when compared with the WT and a 1.5-fold increase in the original RL3500 mutant. Mutation of RL0936 decreased desiccation tolerance and lowered the ability to form biofilms when compared with the WT strain. This work has identified a potential interaction between RL0936 and the RL3499-RL3502 operon that is involved in cell envelope development in R. leguminosarum, and has described phenotypic activities to a previously uncharacterized conserved hypothetical gene.
authors.affiliation: Department of Biology, University of Regina, Regina, Saskatchewan S4S 0A2, Canada.
authors.forename: Kara D
authors.initials: KD
authors.lastname: Neudorf
authors.affiliation: Department of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A2, Canada.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Vanderlinde
authors.affiliation: Department of Biology, University of Regina, Regina, Saskatchewan S4S 0A2, Canada.
authors.forename: Dinah D
authors.initials: DD
authors.lastname: Tambalo
authors.affiliation: Department of Biology, University of Regina, Regina, Saskatchewan S4S 0A2, Canada.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Yost
mesh_terms: D000220:Adaptation, Biological; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018441:Biofilms; D002462:Cell Membrane / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism*; D019295:Computational Biology; D004251:DNA Transposable Elements; D003890:Desiccation; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D005816:Genetic Complementation Test; D016296:Mutagenesis; D009154:Mutation; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D016961:Rhizobium leguminosarum / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements