U2AF homology motifs: protein recognition in the RRM world

Genes Dev. 2004 Jul 1;18(13):1513-26. doi: 10.1101/gad.1206204.


Recent structures of the heterodimeric splicing factor U2 snRNP auxiliary factor (U2AF) have revealed two unexpected examples of RNA recognition motif (RRM)-like domains with specialized features for protein recognition. These unusual RRMs, called U2AF homology motifs (UHMs), represent a novel class of protein recognition motifs. Defining a set of rules to distinguish traditional RRMs from UHMs is key to identifying novel UHM family members. Here we review the critical sequence features necessary to mediate protein-UHM interactions, and perform comprehensive database searches to identify new members of the UHM family. The resulting implications for the functional and evolutionary relationships among candidate UHM family members are discussed.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Molecular Sequence Data
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / metabolism*
  • RNA / metabolism*
  • Ribonucleoproteins / chemistry
  • Ribonucleoproteins / metabolism*
  • Sequence Homology, Amino Acid
  • Splicing Factor U2AF


  • Nuclear Proteins
  • Ribonucleoproteins
  • Splicing Factor U2AF
  • RNA