The effect of an ilvA Mu phage insertion on ilv gene expression in Escherichia coli K-12

Physiological analysis of an E. coli K-12 strain carrying a Mu phage integrated into the ilvA structural gene shows that there is a polar affect on ilvD gene expression, whereas, the ilvE gene maintains a normal multivalent regulation response. It was also demonstrated that the ilvC and ilvB genes can be derepressed and repressed in response to ilv multivalent control. These experiments demonstrate that the ilvE structural gene can be regulated independently from the ilvA and ilvD structural genes and that the ilvC structural gene does not require the complete ilvA gene product (threonine deaminase) for its induction.