1AFL

RIBONUCLEASE A IN COMPLEX WITH 5'-DIPHOSPHOADENOSINE 2'-PHOSPHATE AT 1.7 ANGSTROM RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.217 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystal structures of ribonuclease A complexes with 5'-diphosphoadenosine 3'-phosphate and 5'-diphosphoadenosine 2'-phosphate at 1.7 A resolution.

Leonidas, D.D.Shapiro, R.Irons, L.I.Russo, N.Acharya, K.R.

(1997) Biochemistry 36: 5578-5588

  • DOI: 10.1021/bi9700330
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • High-resolution (1.7 A) crystal structures have been determined for bovine pancreatic ribonuclease A (RNase A) complexed with 5'-diphosphoadenosine 3'-phosphate (ppA-3'-p) and 5'-diphosphoadenosine 2'-phosphate (ppA-2'-p), as well as for a native str ...

    High-resolution (1.7 A) crystal structures have been determined for bovine pancreatic ribonuclease A (RNase A) complexed with 5'-diphosphoadenosine 3'-phosphate (ppA-3'-p) and 5'-diphosphoadenosine 2'-phosphate (ppA-2'-p), as well as for a native structure refined to 2.0 A. These nucleotide phosphates are the two most potent inhibitors of RNase A reported so far, with Ki values of 240 and 520 nM, respectively. The binding modes and conformations of ppA-3'-p and ppA-2'-p were found to differ markedly from those anticipated on the basis of earlier structures of RNase A complexes. The key difference is that the 5'-beta-phosphate rather than the 5'-alpha-phosphate of each inhibitor occupies the P1 phosphate binding site. As a consequence, the ribose moieties of the two nucleotides are shifted by approximately 2 A compared to the positions of their counterparts in earlier complexes, and the adenine rings are rotated into unusual syn conformations. Thus, the six-membered and five-membered rings of both adenines are reversed with respect to the others but nonetheless engage in extensive interactions with the residues that form the B2 purine binding site of RNase A. Despite the close structural similarity of the two inhibitors, the puckers of their furanose rings are different: C2'-endo and C3'-endo, respectively. Moreover, their 5'-alpha-phosphates and 3'(2')-monophosphates interact with largely different sets of RNase residues. The results of this crystallographic study emphasize the difficulties inherent in qualitative modeling of protein-inhibitor interactions and the compelling reasons for high-resolution structural studies in which quantitative design of improved inhibitors was enabled. The structures presented here provide a promising starting point for the rational design of tight-binding RNase inhibitors, which may be used as therapeutic agents in restraining the ribonucleolytic activities of RNase homologues such as angiogenin, eosinophil-derived neurotoxin, and eosinophil cationic protein.


    Organizational Affiliation

    School of Biology and Biochemistry, University of Bath, Claverton Down, U.K.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
RIBONUCLEASE A
A, B
124Bos taurusMutation(s): 0 
Gene Names: RNASE1RNS1
EC: 3.1.27.5 (PDB Primary Data), 4.6.1.18 (UniProt)
Find proteins for P61823 (Bos taurus)
Go to UniProtKB:  P61823
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ATR
Query on ATR

Download CCD File 
A, B
2'-MONOPHOSPHOADENOSINE-5'-DIPHOSPHATE
C10 H16 N5 O13 P3
YPTPYQSAVGGMFN-KQYNXXCUSA-N
 Ligand Interaction
CIT
Query on CIT

Download CCD File 
A, B
CITRIC ACID
C6 H8 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
ATRKi:  520   nM  Binding MOAD
ATRKi:  520   nM  PDBBind
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.217 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 101.93α = 90
b = 33.44β = 90.08
c = 73.69γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-03-18
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance