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A gene involved in quinate metabolism is specific to one DNA homology group of Xanthomonas campestris
Author(s) -
Lee Y. A.,
Lo Y. C.,
Yu P. P.
Publication year - 1999
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1046/j.1365-2672.1999.00864.x
Subject(s) - biology , bamhi , xanthomonas campestris , genomic dna , genetics , homology (biology) , plasmid , nucleic acid sequence , microbiology and biotechnology , restriction fragment length polymorphism , gene , acinetobacter calcoaceticus , acinetobacter , genotype , bacteria
A gene involved in quinate metabolism was cloned from Xanthomonas campestris pv. juglandis strain C5. The gene, qumA , located on a 4·2‐kb Kpn I‐ Eco RV fragment in plasmid pQM38, conferred quinate metabolic activity to X. c. pv. celebensis . Tn 3 ‐spice insertional analyses further located the qumA gene on a region of about 3·0 kb within pQM38. Nucleotide sequencing of this 3·0‐kb fragment reveals that the coding region of qumA is 2373 bp, the deduced amino acid sequence of which closely resembles a pyrrolo‐quinoline quinone‐dependent quinate dehydrogenase of Acinetobacter calcoaceticus . A 0·7 kb Sal I‐ Pst I fragment internal to qumA was used as a probe to hybridize against total genomic DNA from 43 pathovars of X. campestris . The fragment hybridized only to total genomic DNA from the four pathovars of DNA homology group 6, X. c. pv. celebensis , X. c. pv. corylina , X. c. pv. juglandis and X. c. pv. pruni , and from X. c. pv. carotae , which belongs to DNA homology group 5. This 0·7 kb fragment was also used as a probe to hybridize Bam HI‐digested total genomic DNAs from the four pathovars of DNA homology group 6 and X. c. pv. carotae . The restriction fragment length polymorphism pattern of DNA homology group 6 was different from that of X. c. pv. carotae . The probe hybridized to a 5·7‐kb Bam HI fragment in all four pathovars of group 6 and to a 6·1‐kb Bam HI fragment in three of four pathovars. It hybridized only to a 9·9‐kb Bam HI fragment in X. c. pv. carotae . Quinate metabolism has previously been reported as a phenotypic property specific to X. campestris DNA homology group 6. Accordingly, a combination of the quinate metabolism phenotypic test and Southern hybridization using a qumA ‐derived probe will be very useful in the identification of pathovars in DNA homology group 6.