2HHP

Structure of yeast poly(A) polymerase in a closed conformation.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

X-ray crystallographic and steady state fluorescence characterization of the protein dynamics of yeast polyadenylate polymerase.

Balbo, P.B.Toth, J.Bohm, A.

(2007) J.Mol.Biol. 366: 1401-1415

  • DOI: 10.1016/j.jmb.2006.12.030
  • Primary Citation of Related Structures:  2O1P

  • PubMed Abstract: 
  • Polyadenylate polymerase (PAP) catalyzes the synthesis of poly(A) tails on the 3'-end of pre-mRNA. PAP is composed of three domains: an N-terminal nucleotide-binding domain (homologous to the palm domain of DNA and RNA polymerases), a middle domain ( ...

    Polyadenylate polymerase (PAP) catalyzes the synthesis of poly(A) tails on the 3'-end of pre-mRNA. PAP is composed of three domains: an N-terminal nucleotide-binding domain (homologous to the palm domain of DNA and RNA polymerases), a middle domain (containing other conserved, catalytically important residues), and a unique C-terminal domain (involved in protein-protein interactions required for 3'-end formation). Previous X-ray crystallographic studies have shown that the domains are arranged in a V-shape such that they form a central cleft with the active site located at the base of the cleft at the interface between the N-terminal and middle domains. In the previous studies, the nucleotides were bound directly to the N-terminal domain and exhibited a conspicuous lack of adenine-specific interactions that would constitute nucleotide recognition. Furthermore, it was postulated that base-specific contacts with residues in the middle domain could occur either as a result of a change in the conformation of the nucleotide or domain movement. To address these issues and to better characterize the structural basis of substrate recognition and catalysis, we report two new crystal structures of yeast PAP. A comparison of these structures reveals that the N-terminal and C-terminal domains of PAP move independently as rigid bodies along two well defined axes of rotation. Modeling of the nucleotide into the most closed state allows us to deduce specific nucleotide interactions involving residues in the middle domain (K215, Y224 and N226) that are proposed to be involved in substrate binding and specificity. To further investigate the nature of PAP domain flexibility, 2-aminopurine labeled molecular probes were employed in steady state fluorescence and acrylamide quenching experiments. The results suggest that the closed domain conformation is stabilized upon recognition of the correct subtrate, MgATP, in an enzyme-substrate ternary complex. The implications of these results on the enzyme mechanism of PAP and the possible role for domain motion in an induced fit mechanism are discussed.


    Organizational Affiliation

    Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Department of Biochemistry, Boston, MA 02111, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Poly(A) polymerase
A
530Saccharomyces cerevisiae (strain ATCC 204508 / S288c)Gene Names: PAP1
EC: 2.7.7.19
Find proteins for P29468 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Go to UniProtKB:  P29468
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
FLC
Query on FLC

Download SDF File 
Download CCD File 
A
CITRATE ANION
C6 H5 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-K
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
FLCIC50: 20000000 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.197 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 58.483α = 90.00
b = 84.918β = 111.78
c = 67.721γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2006-06-28 
  • Released Date: 2007-01-23 
  • Deposition Author(s): Bohm, A., Toth, J.

Revision History 

  • Version 1.0: 2007-01-23
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance