Erwinia stewartii WtsA, a positive regulator of pathogenicity gene expression, is similar to Pseudomonas syringae pv. phaseolicola HrpS

• Published in: Molecular microbiology Vol. 9; no. 3; p. 477
• Main Authors: Frederick, R D, Majerczak, D R, Coplin, D L
• Format: Journal Article
• Language: English
• Published: England 01.08.1993
• Subjects: Amino Acid Sequence; Bacterial Proteins - genetics; Base Sequence; Chromosome Mapping; Crosses, Genetic; DNA-Binding Proteins - genetics; DNA-Directed RNA Polymerases; Erwinia - genetics; Erwinia - pathogenicity; Escherichia coli - genetics; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Genes, Bacterial - genetics; Genes, Reporter; Genetic Complementation Test; Lac Operon; Molecular Sequence Data; Multigene Family - genetics; Mutagenesis; Pseudomonas - genetics; RNA Polymerase Sigma 54; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Sigma Factor - genetics; Species Specificity; Transcription Factors; Virulence - genetics; Zea mays - microbiology
• ISSN: 0950-382X
• DOI: 10.1111/j.1365-2958.1993.tb01709.x

Erwinia stewartii contains a large cluster of wts genes that are required by this bacterium for pathogenicity on corn plants. Three complementation groups within the right half of this cluster, wtsA, wtsC, and wtsB, were previously identified. In this study, WtsA was found to be a positive activator of wtsB::lacZ expression. The wtsA locus was sequenced and a single open reading frame is present within the wtsA locus, which has the capacity to encode a 323 amino acid polypeptide. A corresponding 38 kDa protein was observed in Escherichia coli minicells containing the cloned wtsA gene. The predicted WtsA polypeptide has significant similarity to HrpS from Pseudomonas syringae pv. phaseolicola, as well as other members of the NtrC class of prokaryotic regulatory proteins. Similar to other genes activated by NtrC regulators, wtsB::lacZ expression in E. coli was dependent upon rpoN.