Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 4.2.1.125 extracted from

  • Liu, T.; Zhang, X.; Zhao, F.; Lu, W.
    Molecular simulation and catalytic active sites identification of dammarenediol-II synthase (2017), J. Beijing Inst. Technol., 26, 563-570 .
No PubMed abstract available
Search for more literature for 4.2.1.125

Cloned(Commentary)

Cloned (Comment) Organism
gene DDS, recombinant expression in Saccharomyces cerevisiae strain WTE (strain W303-1a integrated with pRS304-tHMG1 and pRS405-ERG20) from TEF1p-DS-ADH3t vector Panax ginseng

Protein Variants

Protein Variants Comment Organism
C264A site-directed mutagenesis, the mutant shows 53% decreased activity compared to the wild-type enzyme Panax ginseng
C489A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
C568A site-directed mutagenesis, the mutant shows slightly increased activity compared to the wild-type enzyme Panax ginseng
D488A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
F477A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
I559A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
W421A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
W538A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
W616A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
Y263A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
Y268A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng
Y732A site-directed mutagenesis, the mutant shows highly decreased activity compared to the wild-type enzyme Panax ginseng

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
(3S)-2,3-epoxy-2,3-dihydrosqualene + H2O Panax ginseng
-
 dammarenediol II
-
 r

Organism

Organism UniProt Comment Textmining
Panax ginseng Q08IT1
-
-

Reaction

Reaction Comment Organism Reaction ID
dammarenediol II = (3S)-2,3-epoxy-2,3-dihydrosqualene + H2O an unusually complex and flexible reaction mechanism generates this ring system. As a general mechanism, firstly (3S)-2,3-oxidosqualene adopts a preorganized chair-chair-chair conformation, and activated by cationic attack. Then the oxirane ring of (3S)-2,3-oxidosqualene opens, following with a cascade of cation-olefin cyclizations, and generates a cyclic C-20 dammarenyl cation Panax ginseng
a

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
(3S)-2,3-epoxy-2,3-dihydrosqualene + H2O
-
 Panax ginseng dammarenediol II
-
 r
additional information dammarenediol-II synthase (DS) is a kind of 2,3-oxidosqualene-triterpene cyclase that catalyses 2,3-oxidosqualene to form dammarenediol-II. The substrate 2,3-oxidosqualene is cyclized by the enzyme at specific sites, and its particular 6-6-6-5 tetracyclic triterpenoid structure can be developed Panax ginseng ?
-
 ?

Subunits

Subunits Comment Organism
More three-dimensional structure and catalytic active sites structures of dammarenediol-II synthase, homology modelling, overview Panax ginseng

Synonyms

Synonyms Comment Organism
dammarenediol-II synthase
-
 Panax ginseng
DDS
-
 Panax ginseng

General Information

General Information Comment Organism
additional information three-dimensional structure and catalytic active sites structures of dammarenediol-II synthase by homology modeling using human oxidosqualene cyclase 3D models (PDB IDs 1W6K and 1W6J) as templates and by molecular docking simulation between enzyme model and product dammarenediol-II, overview. Residues C568 and C264 play significant roles in the catalytic process of the enzyme. Active site residues are identified: Asp488 initiates the ring forming reaction by protonating the 2,3-oxirane ring, and is activated by strong polar amino acid Cys489 and Cys568. Aromatic residues Trp421, Phe477, Trp538, Tyr263 and Tyr732 may stabilize the intermediate conformation during the cyclization. Cys264, Tyr268 and Ile559 may have relation with a substrate channel that guides 2,3-oxidosqualene into the active site cavity Panax ginseng