the repression of beta-isopropylmalate dehydrogenase , the leu2 gene product , by leucine and leucine plus threonine was unaffected by the transposition of leu2 from its original locus on chromosome iii to a new locus within the ribosomal deoxyribonucleic acid gene cluster on chromosome xii .
C1708726
locus
C0008633
chromosome