RT Journal Article SR Electronic(1) A1 Kisumi, M. A1 Komatsubara, S. A1 Sugiura, M. A1 Chibata, I.YR 1971 T1 Properties of Isoleucine Hydroxamate-resistant Mutants of Serratia marcescens JF Microbiology, VO 69 IS 3 SP 291 OP 297 DO https://doi.org/10.1099/00221287-69-3-291 PB Microbiology Society, SN 1465-2080, AB SUMMARY: Isoleucine hydroxamate-resistant mutants of Serratia marcescens have been isolated. Biochemical examination of the isoleucine-valine biosynthetic enzymes allowed the mutants to be grouped into three classes: I, mutants with increased enzyme levels; II, mutants with feedback inhibition-insensitive l-threonine dehydratase; III, mutants without any alteration in either feedback inhibition or enzyme levels. Of these mutants, class II accumulated isoleucine outside the cells in medium containing l-threonine. Strain IHr3i3, whose l-threonine dehydratase was about 500-fold less sensitive to feedback inhibition when compared with wild-type enzyme, accumulated up to 7 mg. of isoleucine per ml. of medium., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-69-3-291