title: Barnase and barstar: two small proteins to fold and fit together.
abstract: Barnase and barstar are the extracellular ribonuclease and its intracellular inhibitor produced by Bacillus amyloliquefaciens. Both are small single-chain proteins and thus are suitable for application to the study of how a protein's sequence directs its fold. Barnase has neither disulfide bonds nor non-peptide components and unfolds reversibly in what closely approximates a two-state reaction. The genes for both these proteins have been cloned in E. coli. Expression of barstar is necessary to counter the lethal effect of expressed active barnase. Site-directed mutagenesis is being used to answer specific and general questions relating to protein folding and protein-protein interaction.
authors.forename: R W
authors.initials: RW
authors.lastname: Hartley
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012260:Ribonucleases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C057438:barstar protein, Bacillus amyloliquefaciens; D012260:Ribonucleases; C019760:Bacillus amyloliquefaciens ribonuclease