Open AccessPhysical organization of the ilvEDAC genes of Escherichia coli strain K-12
Author(s) -
George M. McCorkle,
Timothy D. Leathers,
H. E. Umbarger
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.1.89
Subject(s) - ecori , heteroduplex , escherichia coli , operon , complementation , microbiology and biotechnology , gene , dna , restriction enzyme , plasmid , cleavage (geology) , biology , ecorv , genetics , pbr322 , bamhi , chemistry , phenotype , paleontology , fracture (geology)
We have determined the physical location of theilvEDAC genes on the restriction cleavage map of theilv region ofEscherichia coli K-12 by two methods: (i ) heteroduplex and endonuclease cleavage analysis of hybrid phages carrying genetically defined parts of theilv cluster and (ii ) complementation analysis and enzyme assays to determineilv gene expression from hybrid plasmids containing DNA restriction fragments of the transducing phage λh80dilv . TheilvEDA andilvC operons occupy 2.4 and 0.9 megadalton sequences of DNA, respectively, and are separated by a region of 0.6-0.75 megadalton. TheilvD region, specifying dihydroxy acid dehydrase, has a maximum coding capacity of about 55,000 daltons of polypeptide. Our results confirm thatilvC is transcribed clockwise on theE. coli K-12 map, in the same direction asilaEDA . A secondary λ attachment site withinilvC has been located on a small (0.45 megadalton)Eco RI fragment. Our results are compared to other physical studies ofilv DNA.