5IPD

Human Histidine Triad Nucleotide Binding Protein 1 (hHint1) nucleoside thiophosphoramidate covalent intermediate complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.188 
  • R-Value Work: 0.158 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Caught before Released: Structural Mapping of the Reaction Trajectory for the Sofosbuvir Activating Enzyme, Human Histidine Triad Nucleotide Binding Protein 1 (hHint1).

Shah, R.Maize, K.M.Zhou, X.Finzel, B.C.Wagner, C.R.

(2017) Biochemistry 56: 3559-3570

  • DOI: 10.1021/acs.biochem.7b00148
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Human histidine triad nucleotide binding protein 1 (hHint1) is classified as an efficient nucleoside phosphoramidase and acyl-adenosine monophosphate hydrolase. Human Hint1 has been shown to be essential for the metabolic activation of nucleotide ant ...

    Human histidine triad nucleotide binding protein 1 (hHint1) is classified as an efficient nucleoside phosphoramidase and acyl-adenosine monophosphate hydrolase. Human Hint1 has been shown to be essential for the metabolic activation of nucleotide antiviral pronucleotides (i.e., proTides), such as the FDA approved hepatitis C drug, sofosbuvir. The active site of hHint1 comprises an ensemble of strictly conserved histidines, including nucleophilic His112. To structurally investigate the mechanism of hHint1 catalysis, we have designed and prepared nucleoside thiophosphoramidate substrates that are able to capture the transiently formed nucleotidylated-His112 intermediate (E*) using time-dependent crystallography. Utilizing a catalytically inactive hHint1 His112Asn enzyme variant and wild-type enzyme, the enzyme-substrate (ES1) and product (EP2) complexes were also cocrystallized, respectively, thus providing a structural map of the reaction trajectory. On the basis of these observations and the mechanistic necessity of proton transfers, proton inventory studies were carried out. Although we cannot completely exclude the possibility of more than one proton in flight, the results of these studies were consistent with the transfer of a single proton during the formation of the intermediate. Interestingly, structural analysis revealed that the critical proton transfers required for intermediate formation and hydrolysis may be mediated by a conserved active site water channel. Taken together, our results provide mechanistic insights underpinning histidine nucleophilic catalysis in general and hHint1 catalysis, in particular, thus aiding the design of future proTides and the elucidation of the natural function of the Hint family of enzymes.


    Organizational Affiliation

    Department of Medicinal Chemistry University of Minnesota , Minneapolis, Minnesota 55455, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Histidine triad nucleotide-binding protein 1
A, B
129Homo sapiensMutation(s): 0 
Gene Names: HINT1 (HINT, PKCI1, PRKCNH1)
EC: 3.-.-.-
Find proteins for P49773 (Homo sapiens)
Go to Gene View: HINT1
Go to UniProtKB:  P49773
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
6CG
Query on 6CG

Download SDF File 
Download CCD File 
A
5'-S-phosphono-5'-thioguanosine
TrpGMPS hydrolysis product
C10 H14 N5 O7 P S
GPKODAQOVIGWBY-UUOKFMHZSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.188 
  • R-Value Work: 0.158 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 78.445α = 90.00
b = 46.241β = 94.78
c = 64.218γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
SCALAdata scaling
PDB_EXTRACTdata extraction
PHENIXrefinement
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2017-03-15
    Type: Initial release
  • Version 1.1: 2017-07-05
    Type: Database references
  • Version 1.2: 2017-07-26
    Type: Database references