LEAKY MUTATION AND COORDINATE REGULATION OF THE ACCUMULATION OF LYSINE-PRECURSORS IN SACCHAROMYCES

Abstract

One of the lysine auxotrophs (ly12) of Saccharomyces exhibits a residual ability (leakiness) to grow in minimal medium. This mutant accumulates homocitric, cis-homoaconitic and homoisocitric acids both in presence and in absence of lysine. These intermediates accumulate behind the biochemical block and overflow into the culture medium. Accumulation of these intermediates is reduced significantly and simultaneously in presence of lysine compared to the minimal medium.