title: Three-dimensional structure of the alkaline protease of Pseudomonas aeruginosa: a two-domain protein with a calcium binding parallel beta roll motif.
abstract: The three-dimensional structure of the alkaline protease of Pseudomonas aeruginosa, a zinc metalloprotease, has been solved to a resolution of 1.64 A by multiple isomorphous replacement and non-crystallographic symmetry averaging between different crystal forms. The molecule is elongated with overall dimensions of 90 x 35 x 25 A; it has two distinct structural domains. The N-terminal domain is the proteolytic domain; it has an overall tertiary fold and active site zinc ligation similar to that of astacin, a metalloprotease isolated from a European freshwater crayfish. The C-terminal domain consists of a 21-strand beta sandwich. Within this domain is a novel 'parallel beta roll' structure in which successive beta strands are wound in a right-handed spiral, and in which Ca2+ ions are bound within the turns between strands by a repeated GGXGXD sequence motif, a motif that is found in a diverse group of proteins secreted by Gram-negative bacteria.
authors.affiliation: Beckman Laboratories for Structural Biology, Department of Cell Biology, Stanford University School of Medicine, CA 94305.
authors.forename: U
authors.initials: U
authors.lastname: Baumann
authors.forename: S
authors.initials: S
authors.lastname: Wu
authors.forename: K M
authors.initials: KM
authors.lastname: Flaherty
authors.forename: D B
authors.initials: DB
authors.lastname: McKay
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003400:Astacoidea; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D016384:Consensus Sequence; D008666:Metalloendopeptidases / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D015032:Zinc / Q000378:metabolism
chemical_list: D008666:Metalloendopeptidases; C071288:astacin; D015032:Zinc; D002118:Calcium