title: Gene from tropical Bacillus sphaericus encoding a protease closely related to subtilisins from Antarctic bacilli.
abstract: We undertook to identify the protease(s) involved in the in vivo degradation of the 100 kDa mosquitocidal toxin (Mtx) from Bacillus sphaericus SSII-1 and isolated a B. sphaericus SSII-1 gene flanked upstream by a typical Shine-Dalgarno ribosome binding site and downstream by a strong rho-independent transcription terminator. The predicted ORF encodes a 432 amino acid protein with significant homology throughout its sequence to two subtilisin-like serine proteases from the Antarctic psychrophilic (cold-adapted) bacilli, TA39 and TA41. The predicted N-terminal sequence suggests that the B. sphaericus protease is related to sfericase, a partially characterized serine protease from B. sphaericus. Only B. sphaericus strains which produce Mtx-degrading protease activity harbour the subtilisin-like protease gene, suggesting that this protease may be responsible for or contribute to the degradation of Mtx in B. sphaericus SSII-1. A 36-kDa protease with Mtx-degrading activity and similar properties to sfericase was also purified from sporulated cultures of B. sphaericus SSII-1. Further studies are needed to determine the relationship of this protease to sfericase and to the predicted product of the subtilisin-like serine protease gene.
authors.affiliation: Institute of Molecular and Cell Biology, National University of Singapore, Singapore.
authors.forename: M R
authors.initials: MR
authors.lastname: Wati
authors.forename: T
authors.initials: T
authors.lastname: Thanabalu
authors.forename: A G
authors.initials: AG
authors.lastname: Porter
mesh_terms: D000595:Amino Acid Sequence; D000864:Antarctic Regions; D001407:Bacillus / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D013381:Subtilisins / Q000235:genetics*; D014329:Tropical Climate
chemical_list: D012697:Serine Endopeptidases; D013381:Subtilisins; C038978:sfericase