Non-covalent swapped dimer of Bovine Seminal Ribonuclease in complex with 2'-DEOXYCYTIDINE-2'-DEOXYADENOSINE-3',5'-MONOPHOSPHATE

Experimental Data Snapshot

  • Resolution: 2 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report

This is version 1.2 of the entry. See complete history


Structure and Stability of the Non-covalent Swapped Dimer of Bovine Seminal Ribonuclease: AN ENZYME TAILORED TO EVADE RIBONUCLEASE PROTEIN INHIBITOR

Sica, F.Di Fiore, A.Merlino, A.Mazzarella, L.

(2004) J.Biol.Chem. 279: 36753-36760

  • DOI: 10.1074/jbc.M405655200
  • Also Cited By: 3FL3, 3FL1, 3FL0, 3FKZ, 3F8G, 3BCP, 3BCO, 3BCM

  • PubMed Abstract: 
  • A growing number of pancreatic-type ribonucleases (RNases) present cytotoxic activity against malignant cells. The cytoxicity of these enzymes is related to their resistance to the ribonuclease protein inhibitor (RI). In particular, bovine seminal ri ...

    A growing number of pancreatic-type ribonucleases (RNases) present cytotoxic activity against malignant cells. The cytoxicity of these enzymes is related to their resistance to the ribonuclease protein inhibitor (RI). In particular, bovine seminal ribonuclease (BS-RNase) is toxic to tumor cells both in vitro and in vivo. BS-RNase is a covalent dimer with two intersubunit disulfide bridges between Cys(31) of one chain and Cys(32) of the second and vice versa. The native enzyme is an equilibrium mixture of two isomers, MxM and M=M. In the former the two subunits swap their N-terminal helices. The cytotoxic action is a peculiar property of MxM. In the reducing environment of cytosol, M=M dissociates into monomers, which are strongly inhibited by RI, whereas MxM remains as a non-covalent dimer (NCD), which evades RI. We have solved the crystal structure of NCD, carboxyamidomethylated at residues Cys(31) and Cys(32) (NCD-CAM), in a complex with 2'-deoxycitidylyl(3'-5')-2'-deoxyadenosine. The molecule reveals a quaternary structural organization much closer to MxM than to other N-terminal-swapped non-covalent dimeric forms of RNases. Model building of the complexes between these non-covalent dimers and RI reveals that NCD-CAM is the only dimer equipped with a quaternary organization capable of interfering seriously with the binding of the inhibitor. Moreover, a detailed comparative structural analysis of the dimers has highlighted the residues, which are mostly important in driving the quaternary structure toward that found in NCD-CAM.

    Related Citations: 
    • The unswapped chain of bovine seminal ribonuclease: Crystal structure of the free and liganded monomeric derivative
      Sica, F.,Di Fiore, A.,Zagari, A.,Mazzarella, L.
      (2003) Proteins 52: 263
    • Population shift vs induced fit: the case of bovine seminal ribonuclease swapping dimer
      Merlino, A.,Vitagliano, L.,Sica, F.,Zagari, A.,Mazzarella, L.
      (2004) Biopolymers 73: 689
    • A potential allosteric subsite generated by domain swapping in bovine seminal ribonuclease
      Vitagliano, L.,Adinolfi, S.,Sica, F.,Merlino, A.,Zagari, A.,Mazzarella, L.
      (1999) J.Mol.Biol. 293: 569
    • Binding of a substrate analog to a domain swapping protein: X-ray structure of the complex of bovine seminal ribonuclease with uridylyl(2',5')adenosine
      Vitagliano, L.,Adinolfi, S.,Riccio, A.,Sica, F.,Zagari, A.,Mazzarella, L.
      (1998) Protein Sci. 7: 1691
    • Swapping structural determinants of ribonucleases: an energetic analysis of the hinge peptide 16-22
      Mazzarella, L.,Vitagliano, L.,Zagari, A.
      (1995) Proc.Natl.Acad.Sci.USA 92: 3799
    • Bovine seminal ribonuclease: structure at 1.9 A resolution
      Mazzarella, L.,Capasso, S.,Demasi, D.,Dilorenzo, G.,Mattia, C.A.,Zagari, A.
      (1993) Acta Crystallogr.,Sect.D 49: 389
    • Crystal structure of the dimeric unswapped form of bovine seminal ribonuclease
      Berisio, R.,Sica, F.,De Lorenzo, C.,Di Fiore, A.,Piccoli, R.,Zagari, A.,Mazzarella, L.
      (2003) FEBS Lett. 554: 105

    Organizational Affiliation

    Dipartimento di Chimica, Università degli Studi di Napoli Federico II, Via Cynthia, 80126 Naples, Italy.


Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ribonuclease, seminal
A, B
124Bos taurusMutation(s): 0 
Gene Names: SRN
Find proteins for P00669 (Bos taurus)
Go to UniProtKB:  P00669
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
Query on CPA

Download SDF File 
Download CCD File 
A, B
C19 H25 N8 O9 P
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
Query on YCM
A, B
Experimental Data & Validation

Experimental Data

  • Resolution: 2 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.206 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 41.471α = 90.00
b = 69.689β = 90.00
c = 110.804γ = 90.00
Software Package:
Software NamePurpose
X-PLORmodel building
HKL-2000data reduction
SCALEPACKdata scaling
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-09-14
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance