2024-03-29T00:04:29Z
https://niigata-u.repo.nii.ac.jp/oai
oai:niigata-u.repo.nii.ac.jp:00001562
2022-12-15T03:34:13Z
453:454
485:486:487
Functional analyses of Tyr420 and Leu607 of Alicyclobacillus acidocaldarius squalene-hopene cyclase. Neoachillapentaene, a novel triterpene with the 1, 5, 6-trimethylcyclohexene moiety produced through a folding of the constrained boat structure.
Sato, Tsutomu
Sasahara, Shigehiro
Yamakami, Toshiyuki
Hoshino, Tsutomu
squalene
hopene
terpene cyclase
un-natural natural product
Alicyclobacillus acidocaldarius
The functions of Tyr420 and Leu607 were analyzed by constructing various site-directed mutants. The mutation at position 420 into Ala and Gly gave bicyclic α- and γ-polypodatetraene in significant amounts, but with a trace amount of tricyclic malabaricatriene. The kinetic data for and the product distribution of the Y420F mutant indicate that the major function of Tyr420 is to stabilize the 6/6-fused bicyclic cation. Mutation experiments on Leu607 demonstrate that the appropriate steric bulk size at position 607 is required to strongly bind with the product-like conformation formed during the polycyclization process. Introduction of the bulkiest Tip residue into 420 or 607 led to the production of a novel monocyclic triterpene having the (5R, 6R)-1,5,6-trimethylcyclohexene ring, named neoachillapentaene,indicating that the enzymatic cyclization proceeded via a constrained boat structure. Folding of the squalene molecule into a boat conformation by squalene cyclase has not been reported before.
Japan Society for Bioscience, Biotechnology, and Agrochemistry
2002
eng
journal article
VoR
http://hdl.handle.net/10191/6339
https://niigata-u.repo.nii.ac.jp/records/1562
http://doi.org/10.1271/bbb.66.1660
AA10824164
0916-8451
Bioscience, Biotechnology, and Biochemistry
66
8
1660
1670
https://niigata-u.repo.nii.ac.jp/record/1562/files/07_0015.pdf
application/pdf
355.4 kB
2019-07-29