Boonchird C, Messenguy F, Dubois E
Erfelijkheidsleer en Microbiologie, Vrije Universiteit, Brussels, Belgium.
Eur J Biochem. 1991 Jul 15;199(2):325-35. doi: 10.1111/j.1432-1033.1991.tb16128.x.
In Saccharomyces cerevisiae, the ARG5/ARG6 locus encodes both acetylglutamate kinase and acetylglutamyl-phosphate reductase, localized in the mitochondria. Genetic analysis, determination of the nucleotide sequence of the ARG5/ARG6 gene and identification of the transcript indicate that it encodes a single translation product containing two enzyme activities. However, analysis of cellular extracts revealed that the activities are completely separable. In this work, we define different domains in the ARG5/ARG6 polypeptide; a mitochondrial target sequence and the acetylglutamate-kinase and acetylglutamyl-phosphate-reductase domains. We show that deletions in the N-terminal end of the protein and point mutations in the junction region between the acetylglutamate-kinase and acetylglutamyl-phosphate-reductase domains lead to the accumulation of large precursor. Our data support the idea that import of the ARG5/ARG6 precursor into the mitochondria is required for its processing into two mature enzymes.
