The U-box protein family in plants

Trends Plant Sci. 2001 Aug;6(8):354-8. doi: 10.1016/s1360-1385(01)01960-4.


The U-box is a highly conserved domain recently identified at the C terminus of yeast UFD2, an E4 ubiquitination factor. In yeast, UFD2 is the only U-box-containing protein, but there are two UFD2 homologs and several other proteins containing a U-box domain in humans. Intriguingly, a database search revealed 37 predicted proteins containing a U-box in Arabidopsis. The plant U-box (PUB) proteins form five distinct subclasses, suggesting that they play diverse roles. The ARC1 gene from Brassica, required for self-incompatibility, is currently the only PUB gene functionally characterized. Here, we discuss the characteristics and possible functions of the PUB gene family.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Arabidopsis / genetics*
  • Carrier Proteins / genetics
  • Fungal Proteins / genetics
  • Genes, Plant*
  • Humans
  • Molecular Sequence Data
  • Multigene Family
  • Phylogeny
  • Plant Proteins / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitin-Protein Ligases*
  • Ubiquitins / genetics


  • Carrier Proteins
  • Fungal Proteins
  • Plant Proteins
  • Saccharomyces cerevisiae Proteins
  • Ubiquitins
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitin-Protein Ligases
  • UFD2 protein, S cerevisiae