 |
PDBsum entry 2ps8
|
|
|
|
References listed in PDB file
|
 |
|
Key reference
|
|
|
Title
|
|
Structural and mechanistic analysis of trichodiene synthase using site-Directed mutagenesis: probing the catalytic function of tyrosine-295 and the asparagine-225/serine-229/glutamate-233-Mg2+b motif.
|
|
|
Authors
|
|
L.S.Vedula,
J.Jiang,
T.Zakharian,
D.E.Cane,
D.W.Christianson.
|
|
|
Ref.
|
|
Arch Biochem Biophys, 2008,
469,
184-194.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Trichodiene synthase from Fusarium sporotrichioides contains two metal
ion-binding motifs required for the cyclization of farnesyl diphosphate: the
"aspartate-rich" motif D(100)DXX(D/E) that coordinates to Mg2+A and Mg2+C, and
the "NSE/DTE" motif N(225)DXXSXXXE that chelates Mg2+B (boldface indicates metal
ion ligands). Here, we report steady-state kinetic parameters, product array
analyses, and X-ray crystal structures of trichodiene synthase mutants in which
the fungal NSE motif is progressively converted into a plant-like DDXXTXXXE
motif, resulting in a degradation in both steady-state kinetic parameters and
product specificity. Each catalytically active mutant generates a different
distribution of sesquiterpene products, and three newly detected sesquiterpenes
are identified. In addition, the kinetic and structural properties of the Y295F
mutant of trichodiene synthase were found to be similar to those of the
wild-type enzyme, thereby ruling out a proposed role for Y295 in catalysis.
|
|
|
|
|
|
|
