Dataset Information

Characterization of genes required for pilus expression in Pseudomonas syringae pathovar phaseolicola.

ABSTRACT: Nonpiliated, phage phi 6-resistant mutants of Pseudomonas syringae pv. phaseolicola were generated by Tn5 transposon mutagenesis. A P. syringae pv. phaseolicola LR700 cosmid library was screened with Tn5-containing EcoRI fragments cloned from nonpiliated mutants. The cosmid clone pVK253 complemented the nonpiliated mutant strain HB2.5. A 3.8-kb sequenced region spanning the Tn5 insertion site contained four open reading frames. The transposon-inactivated gene, designated pilP, is 525 bp long, potentially encoding a 19.1-kDa protein precursor that contains a typical membrane lipoprotein leader sequence. Generation of single mutations in each of the three remaining complete open reading frames by marker exchange also resulted in a nonpiliated phenotype. Expression of this gene region by the T7 expression system in Escherichia coli resulted in four polypeptides of approximately 39, 26, 23, and 18 kDa, in agreement with the sizes of the open reading frames. The three genes upstream of pilP were designated pilM (39 kDa), pilN (23 kDa), and pilO (26 kDa). The processing of the PilP precursor into its mature form was shown to be inhibited by globomycin, a specific inhibitor of signal peptidase II. The gene region identified shows a high degree of homology to a gene region reported to be required for Pseudomonas aeruginosa type IV pilus production.

SUBMITTER: Roine E

PROVIDER: S-EPMC177672 | biostudies-other | 1996 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Characterization of genes required for pilus expression in Pseudomonas syringae pathovar phaseolicola.

Roine E E Nunn D N DN Paulin L L Romantschuk M M

Journal of bacteriology 19960101 2

Nonpiliated, phage phi 6-resistant mutants of Pseudomonas syringae pv. phaseolicola were generated by Tn5 transposon mutagenesis. A P. syringae pv. phaseolicola LR700 cosmid library was screened with Tn5-containing EcoRI fragments cloned from nonpiliated mutants. The cosmid clone pVK253 complemented the nonpiliated mutant strain HB2.5. A 3.8-kb sequenced region spanning the Tn5 insertion site contained four open reading frames. The transposon-inactivated gene, designated pilP, is 525 bp long, po ...[more]

PMID: 8550460

Similar Datasets

Project description:UnlabelledPlant-pathogenic bacteria are able to integrate information about their environment and adjust gene expression to provide adaptive functions. AlgU, an extracytoplasmic function (ECF) sigma factor encoded by Pseudomonas syringae, controls expression of genes for alginate biosynthesis and genes involved with resisting osmotic and oxidative stress. AlgU is active while these bacteria are associated with plants, where its presence supports bacterial growth and disease symptoms. We found that AlgU is an important virulence factor for P. syringae pv. tomato DC3000 but that alginate production is dispensable for disease in host plants. This implies that AlgU regulates additional genes that facilitate bacterial pathogenesis. We used transcriptome sequencing (RNA-seq) to characterize the AlgU regulon and chromatin immunoprecipitation sequencing (ChIP-seq) to identify AlgU-regulated promoters associated with genes directly controlled by this sigma factor. We found that in addition to genes involved with alginate and osmotic and oxidative stress responses, AlgU regulates genes with known virulence functions, including components of the Hrp type III secretion system, virulence effectors, and the hrpL and hrpRS transcription regulators. These data suggest that P. syringae pv. tomato DC3000 has adapted to use signals that activate AlgU to induce expression of important virulence functions that facilitate survival and disease in plants.ImportancePlant immune systems produce antimicrobial and bacteriostatic conditions in response to bacterial infection. Plant-pathogenic bacteria are adapted to suppress and/or tolerate these conditions; however, the mechanisms controlling these bacterial systems are largely uncharacterized. The work presented here provides a mechanistic explanation for how P. syringae pv. tomato DC3000 coordinates expression of multiple genetic systems, including those dedicated to pathogenicity, in response to environmental conditions. This work demonstrates the scope of AlgU regulation in P. syringae pv. tomato DC3000 and characterizes the promoter sequence regulated by AlgU in these bacteria.

Dataset Information

Characterization of genes required for pilus expression in Pseudomonas syringae pathovar phaseolicola.

Publications

Characterization of genes required for pilus expression in Pseudomonas syringae pathovar phaseolicola.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets