J. Biol. Chem., Vol. 259, Issue 5, 2845-2849, Mar, 1984
Independent loci for the structural genes of the yeast mitochondrial alpha and beta ATPase subunits
A Vassarotti, M Boutry, AM Colson and A Goffeau
In the yeast Schizosaccharomyces pombe, the structural gene mutations
A23-13 (alpha-) and B59-1 (beta-) which totally prevent the expression of
either the alpha or the beta subunits of the mitochondrial ATPase, were
shown by classical genetic mapping studies to be both located on chromosome
I but genetically unlinked. It is concluded that the structural genes ATP1
and ATP2 for the alpha and beta subunits of the mitochondrial ATPase are
not organized in a cluster. By both meiotic recombination frequency
analysis and gene transfer studies, three single nuclear mutations
affecting to different extents the electrophoretic mobility of the beta
polypeptide were located on the chromosome I very close to the mutation
B59-1 (beta-). Two mutations involved a defective ATPase activity and the
inability to grow on glycerol (gly). One of these mutants E5-23 (beta")
exhibited a beta subunit of slightly reduced electrophoretic mobility. The
other mutation F1-10 (beta) was associated with a beta subunit of normal
electrophoretic mobility. The plasmid pMa2 (Boutry, M., Vassarotti, A.,
Ghislain, M., Douglas, M., Goffeau, A. (1984) J. Biol. Chem. 259, 2840-
2844) containing the structural gene for the beta subunit complemented the
mutants E5-23 (beta") and F1-10 (beta) as well as B59-1 (beta-). These
three mutations are therefore likely to affect the beta structural gene
itself or a very contiguous gene contained in the 5.4- kilobase genomic
insert of pMa2. The mutation F1-10 (beta) was mapped between E5-23 (beta")
and B59-1 (beta-) by analysis of the meiotic recombination frequencies.
Another mutation F25-28-11 (beta') was responsible for an appreciable
decrease of electrophoretic mobility of the beta subunit which, however,
did not affect either the ATPase activity or the ability to grow on
glycerol (GLY). This mutant transformed by pMa2 was able to express the
structural gene for the wild type beta subunit and the resulting
transformants synthesized and assembled both the beta and beta' subunits.
It is concluded that the mutation F25-28-11 (beta') also affects the
structural gene for the beta subunit and does not affect genes controlling
the processing machinery.