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PDBsum entry 1nyl
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Trna-Dependent active site assembly in a class i aminoacyl-Trna synthetase.
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Authors
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L.D.Sherlin,
J.J.Perona.
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Ref.
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Structure, 2003,
11,
591-603.
[DOI no: ]
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PubMed id
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Abstract
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The crystal structure of ligand-free E. coli glutaminyl-tRNA synthetase (GlnRS)
at 2.4 A resolution shows that substrate binding is essential to construction of
a catalytically proficient active site. tRNA binding generates structural
changes throughout the enzyme, repositioning key active site peptides that bind
glutamine and ATP. The structure gives insight into longstanding questions
regarding the tRNA dependence of glutaminyl adenylate formation, the coupling of
amino acid and tRNA selectivities, and the roles of specific pathways for
transmission of tRNA binding signals to the active site. Comparative analysis of
the unliganded and tRNA-bound structures shows, in detail, how flexibility is
built into the enzyme architecture and suggests that the induced-fit transitions
are a key underlying determinant of both amino acid and tRNA specificity.
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Figure 5.
Figure 5. Substrate Juxtaposition by Induced Fit(A) Stereo
view of enzyme conformational changes in the vicinity of the
tRNA 3'-end. The tRNA-bound and unliganded enzymes are
superimposed on the basis of equivalent residues in the DNF
domains (see text). tRNA, dark blue; unliganded enzyme, light
blue; complexed enzyme, gray (DNF domain) and pink (ABD). Dotted
red lines indicate hydrogen bonds observed in the GlnRS-tRNA
complex. QSI inhibitor from the complexed structure, red.(B)
Stereo view of enzyme conformational changes in the active site,
with structures superimposed as in (A). Complexed enzyme, gray;
unliganded enzyme, blue; QSI inhibitor, red. The disorder in the
surface loop at Val71 in the unliganded enzyme is shown by the
dotted blue line (right). Dotted red lines indicate hydrogen
bonds observed in the GlnRS-tRNA complex.
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The above figure is
reprinted
by permission from Cell Press:
Structure
(2003,
11,
591-603)
copyright 2003.
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