Expression data from E. coli cells overexpressing GraL for long periods of time

While studying greA expression, we noted presence of an intrinsic terminator in the leader region of greA mRNA transcript. We found this terminator to be quite efficient both in vivo and in vitro. This region seems to be conserved among many enteric bacteria. Judging from fitness experiments, the resulting short RNAs (50-59nt long) exert biological effects. This lead us to propose that greA leader region encodes a novel small non-coding RNA that we collectively call GraL. We used microarrays to detail the effects of GraL after short and longterm overproduction of GraL. E. coli cells harbouring plasmids overexpressing GraL or vector control, were monitored in an effort to elucidate a longterm (constitutive overexpression) or short term (15 min induction with IPTG) effects. This was done in two backgrounds- either in wt E. coli cells, or ppGpp0 cells (delta relA, delta spoT).