SSL2, a suppressor of a stem-loop mutation in the HIS4 leader encodes the yeast homolog of human ERCC-3

Cell. 1992 Jun 12;69(6):1031-42. doi: 10.1016/0092-8674(92)90621-i.


Reversion of haploid, His4- yeast containing a stem-loop mutation in the 5' UTR that blocks HIS4 translation initiation identified four unlinked suppressor genes, SSL1-SSL4, which restore His4+ expression. The SSL2 gene encodes an essential 95 kd protein with ATP-dependent helicase motifs. SSL2 protein is 54% identical to the protein encoded by the human gene, ERCC-3, for which a defective form causes xeroderma pigmentosum and Cockayne's syndrome. An SSL2 allele made to resemble the defective ERCC-3 gene confers UV light hypersensitivity to yeast cells. Hence, SSL2 is the functional homolog of ERCC-3. However, the SSL2 suppressor gene does not restore HIS4 expression by removal of the stem-loop from DNA or the mRNA. We propose that SSL2 and ERCC-3 may have two functions, one defined by a UV repair defect, and a second essential function that is related to gene expression.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • DNA Helicases / genetics*
  • DNA Mutational Analysis
  • DNA Repair*
  • DNA, Fungal / genetics
  • Fungal Proteins / genetics*
  • Genes, Fungal*
  • Genes, Suppressor
  • Humans
  • Hydrogen Bonding
  • Molecular Sequence Data
  • Oligodeoxyribonucleotides / chemistry
  • Protein Biosynthesis*
  • RNA, Messenger / ultrastructure
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Alignment
  • Transcription Factor TFIIH
  • Ultraviolet Rays


  • DNA, Fungal
  • Fungal Proteins
  • Oligodeoxyribonucleotides
  • RNA, Messenger
  • SSL2 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factor TFIIH
  • DNA Helicases

Associated data

  • GENBANK/M84120
  • GENBANK/M84163
  • GENBANK/M84182
  • GENBANK/M94176
  • GENBANK/S72766
  • GENBANK/S72767
  • GENBANK/S72768
  • GENBANK/S72769
  • GENBANK/S72771
  • GENBANK/X63098