>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=90.74  E-value=0.55  Score=28.12  Aligned_cols=42  Identities=24%  Similarity=0.376  Sum_probs=30.2

Q ss_pred             HHHHHHHHHHHHCCCCHHHHHHHHCCCCHHHHHHHHHHH----CCCCC
Q ss_conf             899999999998186588999996785434666677751----45544
Q gi|254780431|r    5 VERIDKLKKFWSEGLSASQIAVQLGGVTRNAVIGKLHRL----FLSNR   48 (178)
Q Consensus         5 derve~LkkLW~eG~SasqIA~~lGgvtRNAVIGK~hRL----gLs~R   48 (178)
T Consensus         3 ~rE~~il-~~~~~G~s~~eIA~~L~-is~~TV~~~~~~i~~Kl~~~~r   48 (57)
T cd06170           3 PREREVL-RLLAEGKTNKEIADILG-ISEKTVKTHLRNIMRKLGVKSR   48 (57)
T ss_pred             HHHHHHH-HHHHCCCCHHHHHHHHC-CCHHHHHHHHHHHHHHHCCCCH
T ss_conf             8999999-99980799999999989-7899999999999998689999