Multivalent regulation of isoleucine-valine transaminase in an Escherichia coli K-12 ilvA deletion strain

Abstract
In a strain of E. coli K-12 lacking threonine deaminase, the enzyme converting .alpha.-ketoisovalerate and .alpha.-keto-.beta.-methylvalerate to valine and isoleucine, respectively, was multivalently repressed by valine, isoleucine and leucine. This activity was due to transaminase B, specified by the ilvE structural gene.