title: Sequence of the gene encoding a highly thermostable neutral proteinase from Bacillus sp. strain EA1: expression in Escherichia coli and characterisation.
abstract: The gene for a highly thermostable neutral proteinase (Npr) was isolated from Bacillus sp. strain EA1 by the polymerase chain reaction using consensus primers based on the sequences of npr genes from related species. The gene was sequenced and shown to be closely related to a neutral proteinase gene from Bacillus caldolyticus strain YP-T; the mature form of the enzyme differing by only a single amino acid. Enzyme samples were prepared from both the native organisms and also from recombinant Escherichia coli expressing the two npr genes. The proteinase from strain EA1 was shown to be significantly more thermostable than that from B. caldolyticus and that this difference is the result of a single amino acid substitution which is situated proximal to a region of the enzyme known to be crucial to conferring thermal stability. The phylogenetic relationship of EA1 to other Bacilli is also described.
authors.affiliation: Centre for Gene Technology, University of Auckland, New Zealand. dj.saul@auckland.ac.nz
authors.forename: D J
authors.initials: DJ
authors.lastname: Saul
authors.forename: L C
authors.initials: LC
authors.lastname: Williams
authors.forename: H S
authors.initials: HS
authors.lastname: Toogood
authors.forename: R M
authors.initials: RM
authors.lastname: Daniel
authors.forename: P L
authors.initials: PL
authors.lastname: Bergquist
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008666:Metalloendopeptidases / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011994:Recombinant Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D008666:Metalloendopeptidases; C085836:Npr protease