Current Genetics

, Volume 34, Issue 6, pp 438–448

YNT20, a bypass suppressor of yme1 yme2, encodes a putative 3′-5′ exonuclease localized in mitochondria of Saccharomyces cerevisiae

  • Theodor Hanekamp
  • P. E. Thorsness

DOI: 10.1007/s002940050418

Cite this article as:
Hanekamp, T. & Thorsness, P. Curr Genet (1999) 34: 438. doi:10.1007/s002940050418


Mutation of YME genes in yeast results in a high rate of mitochondrial DNA escape to the nucleus. The synthetic respiratory growth defect of yme1 yme2 yeast strains is suppressed by recessive mutations in YNT20. Inactivation of YNT20 creates a cold-sensitive respiratory growth defect that is more pronounced in a yme1 background and which is suppressed by yme2. Inactivation of YNT20 causes a qualitative reduction in the rate of mitochondrial DNA escape in yme1, but not yme2, strains, suggesting that YNT20 plays a role in the yme1-mediated mitochondrial DNA escape pathway. YNT20p is a soluble mitochondrial protein that belongs to a subfamily of putative 3′-5′ exonucleases. Furthermore, conserved sequence elements in Yme2p suggest that this protein may also function as an exonuclease.

Key words Mitochondrial DNA escapeMitochondria3′-5′ exonucleaseYeast

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Theodor Hanekamp
    • 1
  • P. E. Thorsness
    • 2
  1. 1.Department of Molecular Biology, University of Wyoming, Laramie, Wyoming 82071-3944, USAUS
  2. 2.Department of Molecular Biology, University of Wyoming, Laramie, WY 82071-3944, USA e-mail: Tel.:+1-307-766-2038 Fax: +1-307-766-5098US