Candida tropicalis expresses two mitochondrial 2-enoyl thioester reductases that are able to form both homodimers and heterodimers.Torkko, J.M., Koivuranta, K.T., Kastaniotis, A.J., Airenne, T.T., Glumoff, T., Ilves, M., Hartig, A., Gurvitz, A., Hiltunen, J.K.
(2003) J.Biol.Chem. 278: 41213-41220
- PubMed: 12890667
- DOI: 10.1074/jbc.M307664200
- PubMed Abstract:
Here we report on the cloning of a Candida tropicalis gene, ETR2, that is closely related to ETR1. Both genes encode enzymatically active 2-enoyl thioester reductases involved in mitochondrial synthesis of fatty acids (fatty acid synthesis type II) a ...
Here we report on the cloning of a Candida tropicalis gene, ETR2, that is closely related to ETR1. Both genes encode enzymatically active 2-enoyl thioester reductases involved in mitochondrial synthesis of fatty acids (fatty acid synthesis type II) and respiratory competence. The 5'- and 3'-flanking (coding) regions of ETR2 and ETR1 are about 90% (97%) identical, indicating that the genes have evolved via gene duplication. The gene products differ in three amino acid residues: Ile67 (Val), Ala92 (Thr), and Lys251 (Arg) in Etr2p (Etr1p). Quantitative PCR analysis and reverse transcriptase-PCR indicated that both genes were expressed about equally in fermenting and ETR1 predominantly respiring yeast cells. Like the situation with ETR1, expression of ETR2 in respiration-deficient Saccharomyces cerevisiae mutant cells devoid of Ybr026p/Etr1p was able to restore growth on glycerol. Triclosan that is used as an antibacterial agent against fatty acid synthesis type II 2-enoyl thioester reductases inhibited growth of FabI overexpressing mutant yeast cells but was not able to inhibit respiratory growth of the ETR2- or ETR1-complemented mutant yeast cells. Resolving of crystal structures obtained via Etr2p and Etr1p co-crystallization indicated that all possible dimer variants occur in the same asymmetric unit, suggesting that similar dimer formation also takes place in vivo.
Biocenter Oulu, Department of Biochemistry, University of Oulu, Finland.