Chapter 15, Problem 11P

The Saccharomyces cerevisiae nuclear gene ARG8 encodes an enzyme that catalyzes a key step in biosynthesis of the amino acid arginine. This protein is normally synthesized on cytoplasmic ribosomes, but then is transported into mitochondria, where the enzyme conducts its functions. In 1996, T. D. Fox and his colleagues constructed a strain of yeast in which a gene encoding the Arg8 protein was itself moved into mitochondria, where functional protein could be synthesized on mitochondrial ribosomes.

a.	How could these investigators move the ARG8 gene from the nucleus into the mitochondria, while permitting the synthesis of active enzyme? In what ways would the investigators need to alter the ARG8 gene to allow it to function in the mitochondria instead of in the nucleus?
b.	Why might these researchers have wished to move the ARG8 gene into mitochondria in the first place?