title: Barnase and barstar. Expression of its cloned inhibitor permits expression of a cloned ribonuclease.
abstract: Barnase is the extracellular ribonuclease of Bacillus amyloliquefaciens and barstar its specific intracellular inhibitor. The gene for barstar has now been cloned and sequenced. When the wild-type gene for barnase is reconstructed from its previously cloned parts on the same plasmid as the barstar gene, the lethal effect of its expression is suppressed. A plasmid has been devised which directs the secretion of 100 mg per active barnase liter by Escherichia coli and another which provides large (500 to 1000 mg/l) yields of barstar. The structure of these plasmids and the derived 89 amino acid sequence of barstar are reported.
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010957:Plasmids; D012260:Ribonucleases / Q000037:antagonists & inhibitors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C057438:barstar protein, Bacillus amyloliquefaciens; D012260:Ribonucleases; C019760:Bacillus amyloliquefaciens ribonuclease