1JTF

Crystal Structure Analysis of VP39-F180W mutant and m7GpppG complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.258 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The "cap-binding slot" of an mRNA cap-binding protein: quantitative effects of aromatic side chain choice in the double-stacking sandwich with cap.

Hu, G.Oguro, A.Li, C.Gershon, P.D.Quiocho, F.A.

(2002) Biochemistry 41: 7677-7687

  • Primary Citation of Related Structures:  1JSZ, 1JTE

  • PubMed Abstract: 
  • The N7-methylguanine portion of the mRNA cap structure interacts with cap-binding proteins via an unusual double-stacking arrangement in which the positively charged cap is sandwiched between two parallel-oriented aromatic protein side chains. Three- ...

    The N7-methylguanine portion of the mRNA cap structure interacts with cap-binding proteins via an unusual double-stacking arrangement in which the positively charged cap is sandwiched between two parallel-oriented aromatic protein side chains. Three-dimensional costructures of cap with two mRNA cap-binding proteins, namely, translational initiation factor eIF4E and VP39 (the vaccinia virus-encoded mRNA cap-specific 2'-O-methyltransferase), have heretofore been reported. Despite striking similarities between the two proteins in the double stack with the cap, the stack differs most notably in the species of stacked side chain donated by the protein. Whereas eIF4E employs two tryptophans, VP39 uses a tyrosine and a phenylalanine. Here, we have generated tryptophan substitutions in VP39. Tryptophan substitution was shown, crystallographically, not to disrupt the maintenance of a bona fide parallel stack. However, the single-tryptophan and double-tryptophan substitutions were associated with increased affinity for cap nucleoside by factors of 10 and 50, respectively. VP39 interacted more strongly with a true substrate (containing portions of RNA downstream of the cap in addition to the cap itself) than with isolated cap nucleoside, by several orders of magnitude. VP39 mutants with tryptophan substitution at position 180 exhibited apparent defects in substrate catalytic rate during the first turnover cycle, indicating the possibility of an exquisite sensitivity of the catalytic center to subtle changes in substrate position brought about by alterations in the cap-binding slot. The X-ray structure of VP39 with a genuine nucleobase analogue of N7-methylguanosine, namely, N7,9-dimethylguanine, indicated that the N7-methylguanosine rotational orientation within the stack is a property of the cap nucleobase itself.


    Organizational Affiliation

    Graduate Program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, Texas 77030, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
VP39
A
307Vaccinia virus (strain Western Reserve)Gene Names: PAPS
EC: 2.1.1.57
Find proteins for P07617 (Vaccinia virus (strain Western Reserve))
Go to UniProtKB:  P07617
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAH
Query on SAH

Download SDF File 
Download CCD File 
A
S-ADENOSYL-L-HOMOCYSTEINE
C14 H20 N6 O5 S
ZJUKTBDSGOFHSH-WFMPWKQPSA-N
 Ligand Interaction
M7G
Query on M7G

Download SDF File 
Download CCD File 
A
7N-METHYL-8-HYDROGUANOSINE-5'-DIPHOSPHATE
C11 H19 N5 O11 P2
QQODJOAVWUWVHJ-KQYNXXCUSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.258 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 84.245α = 90.00
b = 67.741β = 118.11
c = 79.635γ = 90.00
Software Package:
Software NamePurpose
X-PLORmodel building
SAINTdata reduction
SAINTdata scaling
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-07-10
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance