BS-RNase tetramers: an example of domain-swapped oligomers

FEBS Lett. 1996 Dec 2;398(2-3):326-32. doi: 10.1016/s0014-5793(96)01034-4.


In the ribonuclease superfamily, dimericity is a unique feature of bovine seminal RNase (BS-RNase). In about two-thirds of native BS-RNase molecules, the two subunits interchange their N-terminal tails, thus generating domain-swapped dimers (MxM), which mostly responsible for enzyme biological activities and allostericity. Higher molecular weight BS-RNase oligomers can also be prepared [Libonati, M. (1969) Ital. J. Biochem. 18, 407-417.]. This paper reports on BS-RNase tetrameric derivatives which were isolated and enzymatically characterized. The data collected and the analysis of the crystal packing of MxM dimers suggested a structural model for tetramer assembly, in which the four subunits are enchained by multiple domain-swapping events.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Biopolymers
  • Chromatography, High Pressure Liquid
  • Crystallography, X-Ray
  • Cytosine Nucleotides / metabolism
  • Dimerization
  • Electrophoresis, Polyacrylamide Gel
  • Endoribonucleases / chemistry*
  • Endoribonucleases / metabolism
  • Models, Molecular
  • Molecular Weight
  • Protein Conformation*
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • RNA, Fungal / metabolism


  • Biopolymers
  • Cytosine Nucleotides
  • RNA, Fungal
  • cifostodine
  • Endoribonucleases
  • ribonuclease SPL