SAM: a novel motif in yeast sterile and Drosophila polyhomeotic proteins

Protein Sci. 1995 Sep;4(9):1928-30. doi: 10.1002/pro.5560040927.


Single copies of an approximately 65-70 residue domain are shown to be present in the sequences of 14 eukaryotic proteins, including yeast byr2, STE11, ste4, and STE50, which are essential participants in sexual differentiation. This domain, named SAM (sterile alpha motif), appears to participate in other developmental processes because it is also present in Drosophila polyhomeotic gene product and related homologues, which are thought to regulate determination of segmental specification in early embryogenesis. Its appearance in byr2 and STE11, which are MEK kinases, and in proteins containing pleckstrain homology, src homology 3, and discs-large homologous region domains, suggests possible participation in signal transduction pathways.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blood Proteins / chemistry
  • Drosophila melanogaster / chemistry*
  • Fungal Proteins / chemistry*
  • Homeodomain Proteins / chemistry*
  • Molecular Sequence Data
  • Phosphoproteins*
  • Saccharomyces cerevisiae / chemistry*
  • Sequence Alignment
  • Signal Transduction
  • src Homology Domains


  • Blood Proteins
  • Fungal Proteins
  • Homeodomain Proteins
  • Phosphoproteins
  • platelet protein P47