Transcriptional
regulation is of great significance for cells to
maintain homeostasis and, meanwhile, represents an innovative but
less explored means to control biological processes in synthetic biology
and bioengineering. Herein we devised a T7 RNA polymerase (T7RNAP)
variant through replacing an essential lysine located in the catalytic
core (K631) with Nε-acetyl-l-lysine (AcK)
via genetic code expansion. This T7RNAP variant requires the deacetylase
activity of NAD-dependent sirtuins to recover its enzymatic activities
and thereby sustains sirtuin-dependent transcription of the gene of
interest in live cells including bacteria and mammalian cells as well
as in in vitro systems. This T7RNAP variant could link gene transcription
to sirtuin expression and NAD availability, thus holding promise to
support some relevant research