title: X-Ray structure of the antibiotic bacitracin A.
abstract: Bacitracins are a group of widely used peptide antibiotics. There has been interest in determining the three-dimensional structure of the bacitracins. However, solution studies indicate significant flexibility in their structure and to date native bacitracins have resisted attempts at crystallisation despite considerable efforts over a number of years by several groups. Here we report the first three-dimensional X-ray structure of a bacitracin, complexed to a subtilisin proteinase. X-Ray diffraction data were collected using synchrotron radiation in combination with the Image Plate Scanner system. The complex structure including two enzymes, two bacitracins, 220 water molecules and two Ca2+ ions was refined by restrained least-squares to a crystallographic R factor ( = sigma [[Fo-Fc]]/sigma [Fo]]) of 16.3% at 2.0 A.
authors.affiliation: European Molecular Biology Laboratory, Hamburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Pfeffer
authors.forename: W
authors.initials: W
authors.lastname: Höhne
authors.forename: S
authors.initials: S
authors.lastname: Branner
authors.forename: K
authors.initials: K
authors.lastname: Wilson
authors.forename: C
authors.initials: C
authors.lastname: Betzel
mesh_terms: D000595:Amino Acid Sequence; D001414:Bacitracin / Q000031:analogs & derivatives* / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D006860:Hydrogen Bonding; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry; D011487:Protein Conformation; D013381:Subtilisins / Q000737:chemistry; D014867:Water; D014961:X-Ray Diffraction
chemical_list: D046911:Macromolecular Substances; D010455:Peptides; D014867:Water; D001414:Bacitracin; C026461:bacitracin A; D013381:Subtilisins; D002118:Calcium