Elg1, an alternative subunit of the RFC clamp loader, preferentially interacts with SUMOylated PCNA

Oren Parnas, Adi Zipin-Roitman, Boris Pfander, Batia Liefshitz, Yuval Mazor, Shay Ben-Aroya, Stefan Jentsch, Martin Kupiec

Research output: Contribution to journalArticlepeer-review

86 Scopus citations


Replication-factor C (RFC) is a protein complex that loads the processivity clamp PCNA onto DNA. Elg1 is a conserved protein with homology to the largest subunit of RFC, but its function remained enigmatic. Here, we show that yeast Elg1 interacts physically and genetically with PCNA, in a manner that depends on PCNA modification, and exhibits preferential affinity for SUMOylated PCNA. This interaction is mediated by three small ubiquitin-like modifier (SUMO)-interacting motifs and a PCNA-interacting protein box close to the N-terminus of Elg1. These motifs are important for the ability of Elg1 to maintain genomic stability. SUMOylated PCNA is known to recruit the helicase Srs2, and in the absence of Elg1, Srs2 and SUMOylated PCNA accumulate on chromatin. Strains carrying mutations in both ELG1 and SRS2 exhibit a synthetic fitness defect that depends on PCNA modification. Our results underscore the importance of Elg1, Srs2 and SUMOylated PCNA in the maintenance of genomic stability.

Original languageEnglish (US)
Pages (from-to)2611-2622
Number of pages12
JournalEMBO Journal
Issue number15
StatePublished - Aug 4 2010
Externally publishedYes


  • PCNA modification
  • genome stability
  • postreplicational repair

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)


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