title: Molecular cloning of an ornithine-activating fragment of the gramicidin S synthetase 2 gene from Bacillus brevis and its expression in Escherichia coli.
abstract: Partially digested chromosomal DNA of Bacillus brevis ATCC 9999, a producer of the cyclic peptide antibiotic gramicidin S, was ligated into the BamHI site of the Escherichia coli expression vector pUR2-Bam. The ligated molecules were used to transfer E. coli to ampicillin resistance. Of 5 X 10(3) colonies tested by in situ immunoassay for a cross-reaction with antibodies against the gramicidin S synthetase 2, 6 colonies were found to be immunoreactive. A clone designated MK2, which had a 3.9-kilobase insert of B. brevis DNA, directed in E. coli under the lac promoter control the synthesis of polypeptides that were cross-reactive with the antibody to the gramicidin S synthetase 2. Partial purification of the gene products by gel filtration revealed a major fraction with an approximate molecular weight of 140,000 and with specific ornithine-dependent ATP-32PPi and 2'-dATP-32PPi exchange activities. These unique activities of the gramicidin S synthetase 2 were not detected in the E. coli strain harboring the vector.
mesh_terms: D000591:Amino Acid Isomerases / Q000235:genetics*; D001407:Bacillus / Q000201:enzymology / Q000235:genetics*; D003001:Cloning, Molecular; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics*; D009097:Multienzyme Complexes / Q000235:genetics*; D009952:Ornithine / Q000378:metabolism*; D010453:Peptide Synthases / Q000235:genetics*
chemical_list: D004274:DNA, Recombinant; D009097:Multienzyme Complexes; D009952:Ornithine; D000591:Amino Acid Isomerases; D010453:Peptide Synthases; C020831:gramicidin-S-synthetase 2