4PEQ

Structure of bovine ribonuclease inhibitor complexed with bovine ribonuclease I


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.21 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.176 
  • R-Value Observed: 0.177 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Functional evolution of ribonuclease inhibitor: insights from birds and reptiles.

Lomax, J.E.Bianchetti, C.M.Chang, A.Phillips, G.N.Fox, B.G.Raines, R.T.

(2014) J Mol Biol 426: 3041-3056

  • DOI: 10.1016/j.jmb.2014.06.007
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Ribonuclease inhibitor (RI) is a conserved protein of the mammalian cytosol. RI binds with high affinity to diverse secretory ribonucleases (RNases) and inhibits their enzymatic activity. Although secretory RNases are found in all vertebrates, the ex ...

    Ribonuclease inhibitor (RI) is a conserved protein of the mammalian cytosol. RI binds with high affinity to diverse secretory ribonucleases (RNases) and inhibits their enzymatic activity. Although secretory RNases are found in all vertebrates, the existence of a non-mammalian RI has been uncertain. Here, we report on the identification and characterization of RI homologs from chicken and anole lizard. These proteins bind to RNases from multiple species but exhibit much greater affinity for their cognate RNases than for mammalian RNases. To reveal the basis for this differential affinity, we determined the crystal structure of mouse, bovine, and chicken RI·RNase complexes to a resolution of 2.20, 2.21, and 1.92Å, respectively. A combination of structural, computational, and bioinformatic analyses enabled the identification of two residues that appear to contribute to the differential affinity for RNases. We also found marked differences in oxidative instability between mammalian and non-mammalian RIs, indicating evolution toward greater oxygen sensitivity in RIs from mammalian species. Taken together, our results illuminate the structural and functional evolution of RI, along with its dynamic role in vertebrate biology.


    Organizational Affiliation

    Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA. Electronic address: rtraines@wisc.edu.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ribonuclease pancreatic
A, C
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

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Ribonuclease/angiogenin inhibitor 1
B, D
456Bos taurusMutation(s): 0 
Gene Names: RNH1
Find proteins for Q3SZN8 (Bos taurus)
Go to UniProtKB:  Q3SZN8
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.21 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.176 
  • R-Value Observed: 0.177 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 117.792α = 90
b = 123.55β = 90
c = 179.301γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-06-25
    Type: Initial release
  • Version 1.1: 2014-07-02
    Changes: Database references
  • Version 1.2: 2014-09-24
    Changes: Structure summary
  • Version 1.3: 2014-10-01
    Changes: Database references
  • Version 1.4: 2017-11-22
    Changes: Database references, Derived calculations, Other, Refinement description, Source and taxonomy