Characterization of novel rad6/ubc2 ubiquitin-conjugating enzyme mutants in yeast

Curr Genet. 2000 Apr;37(4):221-33. doi: 10.1007/s002940050523.


Null mutations in the RAD6/UBC2 gene encoding an E2 ubiquitin-conjugating enzyme cause deficiencies in DNA repair, N-end-rule protein degradation, sporulation and telomeric silencing, and alter the preferred integration positions for Ty1 retrotransposons. Here we selected for mutants of RAD6 that cause a release of telomeric silencing. Some alleles retained nearly wild-type ability for sporulation, DNA repair and the degradation of proteins. Alteration in Ty1 integration-site bias accompanied some of these alleles. The possibility that some mutations specifically affect binding of an unknown protein that works with Rad6 in its silencing role, but is not required for DNA repair or N-end-rule activity, is discussed in terms of the Rad6 crystal structure.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Blotting, Western
  • Crystallography, X-Ray
  • DNA Repair / genetics
  • Gene Silencing
  • Ligases / genetics*
  • Ligases / metabolism
  • Models, Molecular
  • Mutation
  • Retroelements
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / growth & development
  • Saccharomyces cerevisiae Proteins*
  • Spores, Fungal / genetics
  • Telomere
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitins / metabolism
  • Ultraviolet Rays


  • Retroelements
  • Saccharomyces cerevisiae Proteins
  • Ubiquitins
  • RAD6 protein, S cerevisiae
  • Ubiquitin-Conjugating Enzymes
  • Ligases