Premium
Genetic analysis of the Erwinia chrysanthemi 3937 chrysobactin iron‐transport system: characterization of a gene cluster involved in uptake and biosynthetic pathways
Author(s) -
Franza T.,
Enard C.,
Gijsegem F.,
Expert D.
Publication year - 1991
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1991.tb00778.x
Subject(s) - cosmid , biology , genetics , locus (genetics) , escherichia coli , plasmid , gene cluster , operon , gene , microbiology and biotechnology , genomic dna , homology (biology) , genomic library , restriction map , southern blot , dna , peptide sequence
Summary Twenty of the twenty‐two MudII1734 insertions impairing the chrysobactin iron‐assimilation system of Erwinia chrysanthemi 3937 were localized to a 50kbp genomic insert contained in the R‐prime plasmid, R′4 (Enard et al., 1988). Using the conjugative plasmid pULB1 10 (RP4::mini‐Mu) and the generalized transducing phage ΦEC2, we located this iron‐transport region and the two unlinked mutations on the chromosome linkage map. Chrysobactin is a catechol‐type siderophore and, as we have previously observed with the entA locus of Escherichia coli , the E. chrysanthemi ‐derived R′4 was found to complement E. coli entB and entE mutations. A 2.9 kb Eco Ri and a 4.8kb BamHI fragment in the R′4 sharing homology with the E. coli entCEBAP15 operon DNA were subcloned. These fragments were used as DNA/DNA hybridization probes to screen a wild‐type gene library, yielding a recombinant cosmid (pEC7) able to complement mutations disrupting the 2,3‐drhydroxy‐benzoic acid biosynthetic pathway in both Erwinia and Escherichia spp. as well as the E. coli entE mutation. Physical mapping of the genomic MudII1734 insertions corresponding to these mutations led to the identification of a cluster of genes confined to a DNA sequence of about 10 kb required for both biosynthetic and receptor functions.