title: The multiple roles of hypothetical gene BPSS1356 in Burkholderia pseudomallei.
abstract: Burkholderia pseudomallei is an opportunistic pathogen and the causative agent of melioidosis. It is able to adapt to harsh environments and can live intracellularly in its infected hosts. In this study, identification of transcriptional factors that associate with the β' subunit (RpoC) of RNA polymerase was performed. The N-terminal region of this subunit is known to trigger promoter melting when associated with a sigma factor. A pull-down assay using histidine-tagged B. pseudomallei RpoC N-terminal region as bait showed that a hypothetical protein BPSS1356 was one of the proteins bound. This hypothetical protein is conserved in all B. pseudomallei strains and present only in the Burkholderia genus. A BPSS1356 deletion mutant was generated to investigate its biological function. The mutant strain exhibited reduced biofilm formation and a lower cell density during the stationary phase of growth in LB medium. Electron microscopic analysis revealed that the ΔBPSS1356 mutant cells had a shrunken cytoplasm indicative of cell plasmolysis and a rougher surface when compared to the wild type. An RNA microarray result showed that a total of 63 genes were transcriptionally affected by the BPSS1356 deletion with fold change values of higher than 4. The expression of a group of genes encoding membrane located transporters was concurrently down-regulated in ΔBPSS1356 mutant. Amongst the affected genes, the putative ion transportation genes were the most severely suppressed. Deprivation of BPSS1356 also down-regulated the transcriptions of genes for the arginine deiminase system, glycerol metabolism, type III secretion system cluster 2, cytochrome bd oxidase and arsenic resistance. It is therefore obvious that BPSS1356 plays a multiple regulatory roles on many genes.
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia.
authors.forename: Hokchai
authors.initials: H
authors.lastname: Yam
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia; Faculty of Agro Based Industry, Universiti Malaysia Kelantan, Jeli, Kelantan, Malaysia.
authors.forename: Ainihayati Abdul
authors.initials: AA
authors.lastname: Rahim
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia.
authors.forename: Suriani
authors.initials: S
authors.lastname: Mohamad
authors.affiliation: Comparative Genomics and Genetics Research Centre, Malaysia Genome Institute, Kajang, Selangor, Malaysia.
authors.forename: Nor Muhammad
authors.initials: NM
authors.lastname: Mahadi
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia.
authors.forename: Uyub Abdul
authors.initials: UA
authors.lastname: Manaf
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia.
authors.forename: Alexander Chong
authors.initials: AC
authors.lastname: Shu-Chien
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia.
authors.forename: Nazalan
authors.initials: N
authors.lastname: Najimudin
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D018441:Biofilms; D016957:Burkholderia pseudomallei / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D009154:Mutation; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases