 |
PDBsum entry 2v0c
|
|
|
|
References listed in PDB file
|
 |
|
Key reference
|
|
|
Title
|
|
An antifungal agent inhibits an aminoacyl-Trna synthetase by trapping tRNA in the editing site.
|
|
|
Authors
|
|
F.L.Rock,
W.Mao,
A.Yaremchuk,
M.Tukalo,
T.Crépin,
H.Zhou,
Y.K.Zhang,
V.Hernandez,
T.Akama,
S.J.Baker,
J.J.Plattner,
L.Shapiro,
S.A.Martinis,
S.J.Benkovic,
S.Cusack,
M.R.Alley.
|
|
|
Ref.
|
|
Science, 2007,
316,
1759-1761.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Aminoacyl-transfer RNA (tRNA) synthetases, which catalyze the attachment of the
correct amino acid to its corresponding tRNA during translation of the genetic
code, are proven antimicrobial drug targets. We show that the broad-spectrum
antifungal 5-fluoro-1,3-dihydro-1-hydroxy-2,1-benzoxaborole (AN2690), in
development for the treatment of onychomycosis, inhibits yeast cytoplasmic
leucyl-tRNA synthetase by formation of a stable tRNA(Leu)-AN2690 adduct in the
editing site of the enzyme. Adduct formation is mediated through the boron atom
of AN2690 and the 2'- and 3'-oxygen atoms of tRNA's3'-terminal adenosine. The
trapping of enzyme-bound tRNA(Leu) in the editing site prevents catalytic
turnover, thus inhibiting synthesis of leucyl-tRNA(Leu) and consequentially
blocking protein synthesis. This result establishes the editing site as a bona
fide target for aminoacyl-tRNA synthetase inhibitors.
|
|
|
|
|
|
|
|
Figure 3.
Fig. 3. AN2690 forms an adduct with the terminal adenosine
(A76) of tRNA^Leu in the editing active site of LeuRS. (A)
Overall structure of the complex of T. thermophilus LeuRS with
tRNA^Leu and AN2690, showing the adenosine-AN2690 adduct
(ball-and-stick model, ringed in red) in the editing site and
leucine (space-filling model) in the synthetic site. The editing
domain is cyan; the catalytic domain, yellow; Zn-1 domain,
purple; the leucyl-specific insertion domain, black; the
anticodon-binding domain, red; the C-terminal domain, gold; zinc
atoms, gray spheres; and tRNA, blue tube. (B) Unbiased
difference map (1.85 Å resolution) for the AMP-AN2690
adduct in the editing site. (C) Diagram showing water molecules
(dark blue spheres) and hydrogen bonds (green dotted lines)
between editing site residues of LeuRS and the AMP-AN2690 adduct
(orange). Amino acid residues that are mutated in the S.
cerevisiae AN2690-resistant mutants are labeled and colored in
purple (table S2). The atoms are colored accordingly: boron,
mauve; fluorine, green; oxygen, red; nitrogen, light blue;
carbon, yellow; and phosphate, purple. (D) Superposition of
bound posttransfer editing substrate analog (Nva2AA, brown) (9)
and the AMP-AN2690 adduct (orange) obtained after superposing
the C  positions of the
editing domain of each complex.
|
|
Figure 4.
Fig. 4. Boron and the oxaborole ring are required for
inhibition of aminoacylation. All reactions were performed in
triplicate, and the mean values were used to determine a median
inhibitory concentration (IC[50]) with Prism 4 (17).
|
|
|
|
|
|
The above figures are
reprinted
by permission from the AAAs:
Science
(2007,
316,
1759-1761)
copyright 2007.
|
|
|
|
|
|
|
