Site-directed mutagenesis of Saccharomyces cerevisiae beta-tubulin: interaction between residue 167 and benzimidazole compounds

FEBS Lett. 1996 Apr 29;385(1-2):7-10. doi: 10.1016/0014-5793(96)00334-1.

Abstract

Benzimidazoles are widely used as anthelmintic agents and systemic fungicides. In susceptible organisms, benzimidazoles bind to beta-tubulin and block microtubule polymerization. To further characterize this interaction, site-directed mutagenesis followed by gene replacement was used to change Saccharomyces cerevisiae beta-tubulin residue Phe-167 to Tyr. Consistent with previous studies, this mutation resulted in at least 3-4-fold decreased sensitivity to the benzimidazole derivatives carbendazim and nocodazole. The Tyr-167 mutant was cold sensitive, implying a direct effect on benzimidazole binding rather than a nonspecific increase in microtubule stability. Surprisingly, the mutant had 8-fold increased sensitivity to the derivative benomyl, which is structurally identical to carbendazim except at position 1. This suggests that residue 167 interacts with benzimidazoles in the vicinity of the 1-position.

Publication types

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

MeSH terms

  • Antifungal Agents / pharmacology*
  • Benomyl / pharmacology
  • Benzimidazoles / pharmacology*
  • Carbamates*
  • Genes, Fungal / genetics
  • Mutagenesis, Site-Directed
  • Nocodazole / pharmacology
  • Saccharomyces cerevisiae / drug effects*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / growth & development
  • Transformation, Genetic
  • Tubulin / chemistry*
  • Tubulin / drug effects*
  • Tubulin / genetics

Substances

  • Antifungal Agents
  • Benzimidazoles
  • Carbamates
  • Tubulin
  • carbendazim
  • Nocodazole
  • Benomyl