More recently it has been shown that the leuO gene is activated by the transcriptional regulators RcsB and BglJ .
the response regulator RcsB activates leuO transcription in conjunction with BglJ , counteracting H-NS repression of leuO transcription
More recently , it was shown that leuO expression in E. coli can be activated by the RcsB regulators .
Also , LeuO expression was detected in a phosphate-restricted media ; and recently it was shown that the expression of the leuO gene can be activated by the RcsB HAS SEVERAL FUNCTIONS IN VIVO Even though LeuO is expressed at very low level in standard laboratory conditions , it seems that in-vivo it has a role in bacterial survival .