The Saccharomyces cerevisiae DNA repair gene RAD23 encodes a nuclear protein containing a ubiquitin-like domain required for biological function

John F. Watkins, Patrick Sung, Louise Prakash, Satya Prakash

Research output: Contribution to journalArticle

199 Scopus citations


In eukaryotes, the posttranslational conjugation of ubiquitin to various cellular proteins marks them for degradation. Interestingly, several proteins have been reported to contain ubiquitin-like (ub-like) domains that are in fact specified by the DNA coding sequences of the proteins. The biological role of the ub-like domain in these proteins is not known; however, it has been proposed that this domain functions as a degradation signal rendering the proteins unstable. Here, we report that the product of the Saccharomyces cerevisiae RAD23 gene, which is involved in excision repair of UV-damaged DNA, bears a ub-like domain at its amino terminus. This finding has presented an opportunity to define the functional significance of this domain. We show that deletion of the ub-like domain impairs the DNA repair function of RAD23 and that this domain can be functionally substituted by the authentic ubiquitin sequence. Surprisingly, RAD23 is highly stable, and the studies reported herein indicate that its ub-like domain does not mediate protein degradation. Thus, in RAD23 at least, the ub-like domain affects protein function in a nonproteolytic manner.

Original languageEnglish (US)
Pages (from-to)7757-7765
Number of pages9
JournalMolecular and Cellular Biology
Issue number12
StatePublished - Dec 1993


ASJC Scopus subject areas

  • Cell Biology
  • Genetics
  • Molecular Biology

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