>cd06170 LuxR_C_like C-terminal DNA-binding domain of LuxR-like proteins. This domain contains a helix-turn-helix motif and binds DNA. Proteins belonging to this group are response regulators; some act as transcriptional activators, others as transcriptional repressors. Many are active as homodimers. Many are two domain proteins in which the DNA binding property of the C-terminal DNA binding domain is modulated by modifications of the N-terminal domain. For example in the case of Lux R which participates in the regulation of gene expression in response to fluctuations in cell-population density (quorum-sensing), a signaling molecule, the pheromone Acyl HSL (N-acyl derivatives of homoserine lactone), binds to the N-terminal domain and leads to LuxR dimerization. For others phophorylation of the N-terminal domain leads to multimerization, for example Escherichia coli NarL and Sinorhizobium melilot FixJ. NarL controls gene expression of many respiratory-related operons when environmental

Probab=97.29  E-value=0.00014  Score=49.33  Aligned_cols=51  Identities=27%  Similarity=0.444  Sum_probs=43.5

Q ss_pred             CCCCCHHHHHHHHCCCCCCCHHHHHHHHHCCCCCCCCCCCHHHHHHHHHHHHCCCCCCCCC
Q ss_conf             2421012344321128834008999986528765777661368899999986014567771
Q gi|254780526|r  149 LPRRERRILEYLMANRGKRVAKTQIFSAIYGLFDEAVEENVVESHISKLRKKLRNKLGFDP  209 (223)
Q Consensus       149 LT~~E~~lL~~L~~~~g~~vsr~~l~~~iwg~~~~~~~~~tv~~~I~rLRkKL~~~~~~~~  209 (223)
T Consensus         1 LT~rE~~il~~~~~--G--~s~~eIA~~L------~is~~TV~~~~~~i~~Kl~~~~r~el   51 (57)
T cd06170           1 LTPREREVLRLLAE--G--KTNKEIADIL------GISEKTVKTHLRNIMRKLGVKSRTQL   51 (57)
T ss_pred             CCHHHHHHHHHHHC--C--CCHHHHHHHH------CCCHHHHHHHHHHHHHHHCCCCHHHH
T ss_conf             98899999999980--7--9999999998------97899999999999998689999999