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Identification of a gene(s) encoding an extracellular protease from Xanthomonas campestris pv. phaseoli
Abstract
An 8-kilobase (kb) BamHI fragment which contains the gene(s) encoding a putative protease was identified on a genomic clone from Xanthomonas campestris pv. phaseoli. The gene(s) involved have been mapped to a region of approximately 3.5-kb by analysis of Tn5-generated mutants and exonuclease III deletion mutants. A protease-deficient Tn5 mutant was recombined into the chromosome of X. c. pv. phaseoli and marker exchange mutants of X. c. pv. phaseoli still retained proteolytic activity on nutrient agar plates supplemented with 1% (w/v) skim milk, indicating the presence of additional protease gene(s) in X. c. pv. phaseoli. However, in plate assays, the zones of proteolysis produced by the marker exchange mutants were consistently smaller for marker exchange mutants when compared with those generated by the wild type strain. Enzyme assays utilizing different protease substrate and protease inhibitor combinations indicated the cloned 8-kb BamHI DNA fragment encodes a divalent cation-requiring serine-type protease. A comparison of protease-deficient mutants with wild type X. c. pv. phaseoli strains tested in Phaseolus vulgaris in vitro revealed no difference in bacterial multiplication or in symptomatoloy.
Subject Area
Plant pathology|Microbiology
Recommended Citation
Fujimoto, Debora Kiyomi, "Identification of a gene(s) encoding an extracellular protease from Xanthomonas campestris pv. phaseoli" (1991). ETD collection for University of Nebraska-Lincoln. AAI9219372.
https://digitalcommons.unl.edu/dissertations/AAI9219372