@article{oai:niigata-u.repo.nii.ac.jp:00001573,
 author = {Sato, Tsutomu and Hoshino, Tsutomu},
 issue = {12},
 journal = {Bioscience, Biotechnology, and Biochemistry},
 month = {},
 note = {In order to clarify the function of the DXDDTA motif in squalene-hopene cyclase and to identify the acidic amino acid residues crucial for the catalysis, site-directed mutagenesis experiments were carried out. The following results were found: (1) residues D374 and D376 work for the initiation of polyolefin cyclization which arises from the proton attack on the terminal double bond; (2) residue D377 stabilizes C-10 carbocation of the initially cyclized A-ring intermediate, leading to subsequent B-ring closure, which was further verified by isolating the partially cyclized monocyclic product; (3) residues D313 and D447 outside the DXDDTA motif were identified as new active sites; (4) the H451 residue is likely to work in the protonated form to enhance the acidity of the carboxyl groups of D374 and/or D376.},
 pages = {2189--2198},
 title = {Functional analysis of the DXDDTA motif in squalene-hopene cyclase by site-directed mutagenesis experiments: initiation site of the polycyclization reaction and stabilization site of the carbocation intermediate of the initially cyclized A-ring.},
 volume = {63},
 year = {1999}
}