1MAU

Crystal structure of Tryptophanyl-tRNA Synthetase Complexed with ATP and Tryptophanamide in a Pre-Transition state Conformation


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.208 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Interconversion of ATP binding and conformational free energies by tryptophanyl-tRNA synthetase: structures of ATP bound to open and closed, pre-transition-state conformations.

Retailleau, P.Huang, X.Yin, Y.Hu, M.Weinreb, V.Vachette, P.Vonrhein, C.Bricogne, G.Roversi, P.Ilyin, V.Carter, C.W.

(2003) J.Mol.Biol. 325: 39-63

  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Binding ATP to tryptophanyl-tRNA synthetase (TrpRS) in a catalytically competent configuration for amino acid activation destabilizes the enzyme structure prior to forming the transition state. This conclusion follows from monitoring the titration of ...

    Binding ATP to tryptophanyl-tRNA synthetase (TrpRS) in a catalytically competent configuration for amino acid activation destabilizes the enzyme structure prior to forming the transition state. This conclusion follows from monitoring the titration of TrpRS with ATP by small angle solution X-ray scattering, enzyme activity, and crystal structures. ATP induces a significantly smaller radius of gyration at pH=7 with a transition midpoint at approximately 8mM. A non-reciprocal dependence of Trp and ATP dissociation constants on concentrations of the second substrate show that Trp binding enhances affinity for ATP, while the affinity for Trp falls with the square of the [ATP] over the same concentration range ( approximately 5mM) that induces the more compact conformation. Two distinct TrpRS:ATP structures have been solved, a high-affinity complex grown with 1mM ATP and a low-affinity complex grown at 10mM ATP. The former is isomorphous with unliganded TrpRS and the Trp complex from monoclinic crystals. Reacting groups of the two individually-bound substrates are separated by 6.7A. Although it lacks tryptophan, the low-affinity complex has a closed conformation similar to that observed in the presence of both ATP and Trp analogs such as indolmycin, and resembles a complex previously postulated to form in the closely-related TyrRS upon induced-fit active-site assembly, just prior to catalysis. Titration of TrpRS with ATP therefore successively produces structurally distinct high- and low-affinity ATP-bound states. The higher quality X-ray data for the closed ATP complex (2.2A) provide new structural details likely related to catalysis, including an extension of the KMSKS loop that engages the second lysine and serine residues, K195 and S196, with the alpha and gamma-phosphates; interactions of the K111 side-chain with the gamma-phosphate; and a water molecule bridging the consensus sequence residue T15 to the beta-phosphate. Induced-fit therefore strengthens active-site interactions with ATP, substantially intensifying the interaction of the KMSKS loop with the leaving PP(i) group. Formation of this conformation in the absence of a Trp analog implies that ATP is a key allosteric effector for TrpRS. The paradoxical requirement for high [ATP] implies that Gibbs binding free energy is stored in an unfavorable protein conformation and can then be recovered for useful purposes, including catalysis in the case of TrpRS.


    Organizational Affiliation

    Department of Biochemistry and Biophysics, University of North Carolina, Mary Ellen Jones Bldg. CB# 7260, Chapel Hill, NC 27599-7260, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
tryptophan-tRNA ligase
A
328Geobacillus stearothermophilusGene Names: trpS
EC: 6.1.1.2
Find proteins for P00953 (Geobacillus stearothermophilus)
Go to UniProtKB:  P00953
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ATP
Query on ATP

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A
ADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O13 P3
ZKHQWZAMYRWXGA-KQYNXXCUSA-N
 Ligand Interaction
NA
Query on NA

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A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
LTN
Query on LTN

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A
L-TRYPTOPHANAMIDE
C11 H13 N3 O
JLSKPBDKNIXMBS-VIFPVBQESA-N
 Ligand Interaction
CIT
Query on CIT

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A
CITRIC ACID
C6 H8 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

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A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

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A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
ATPKd: 0.005 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.208 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 62.133α = 90.00
b = 62.133β = 90.00
c = 217.807γ = 90.00
Software Package:
Software NamePurpose
BUSTER-TNTrefinement
DENZOdata reduction
SCALEPACKdata scaling
SHARPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-01-07
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2018-04-04
    Type: Data collection