In general, all these predicted CRP promoters contain a pseudo-palindromic CRP binding site and most of them also contain a downstream TA-rich σ-factor binding site, therefore they are likely to be true CRP promoters.
Through decades of research, 269 CRP binding sites (RegulonDB release 5.8 [ 21]) in this species have been experimentally identified, which show a pseudo-palindromic consensus in the form of TGTGAN6TCACA.
The inherent flexibility afforded by the DBD-CTD linker allows the DBDs to adjust for optimal binding to multiple pseudo-palindromic BldD DNA boxes.
Recent evidence in E. coli found that MlrA directly binds to a 33 bp palindromic sequence between IHF- and OmpR-binding sites in the upstream sequence of the csgD promoter.
The protein encoded by the T gene is an embryonic nuclear transcription factor that binds to a specific DNA element, the palindromic T-site.
The CRP dimer is activated by the binding of two cAMP molecules to the effector binding domain of each subunit, which causes a conformational change in the DBDs, allowing each to bind to half of a specific pseudo-palindromic DNA sequence in the promoters of the genes that are under CRP regulation [ 13].
Additional targets of IpsA with putative functions in cell wall biogenesis were identified and IpsA was shown to bind to a conserved palindromic motif within the corresponding promoter regions.
Both aldosterone and cortisol bind to a common consensus palindromic DNA sequence, designated originally as a glucocorticoid response element (GRE) [ 38– 41].
bHLH or E-box proteins, such as ATOH8, bind to a palindromic (canonical) core consensus DNA sequence 5′-CANNTG-3′ known as an E-box element, where NN is usually CG or TG (Blackwell et al, 1993).
GT-3b expression is rapidly induced by NaCl and Pseudo-monas syringae infection and GT-3b binds to a GT-like element (GAAAAA) in the promoter of a calmodulin gene (SCaM-4) [ 21].
