Sequence and evolution of the FruR protein of Salmonella typhimurium: a pleiotropic transcriptional regulatory protein possessing both activator and repressor functions which is homologous to the periplasmic ribose-binding protein

Phylogenetic, structural and functional analyses of the LacI‐GalR family of bacterial transcription factors

“…Because almost all branches in the tree (Fig. 1) bear a single protein, and almost all branches stem from positions near the trunk of the unrooted tree, we suggest that at a very early time in evolutionary history, not long after fusion of the DNA binding domain with the ligand binding domain [5], there was tremendous pressure for gene duplication events that gave rise to most of the current, functionally dissimilar members of the LGF. Presumably this time correlated with a time when bacterial carbon metabolism first became subject to stringent and specific transcriptional control by repressors.…”

“…When two or more proteins of the same function from closely related organisms have been sequenced (i.e. FruR from E. coli and S. typhimurium; ScrR from S. typhimurium and K. pneumoniae, or LacI from E. coli and K. pneumoniae), only one of these proteins was selected for presentation [5,10]. Similarly, if two very similar proteins of essentially the same function have been sequenced from a single organism (i.e.…”

“…In 1991, a report from our laboratory presented a phylogenetic analysis of the ten then sequenced members of a family of H-T-H transcriptional regulatory proteins which included the repressors of the lactose, galactose, fructose, and purine operons of E. coli (LacI, GalR, FruR, and PurR, respectively) [5]. These proteins possess small N-terminal H-T-H domains that are involved in DNA binding as well as large C-terminal ligand binding domains that are homologous to the periplasmic sugar binding receptors specific for galactose, arabinose, and ribose [5 9].…”

Regulatory interactions involving the proteins of the phosphotransferase system in enteric bacteria

“…The regions of these proteins exhibiting sequence similarity were the Relative evolutionary distances are provided next to the branches and were determined as described previously [Feng and Doolittle, 1990;Doolittle and Feng, 19901. Abbreviations are provided in the text and in Vartak et al (1991) C-terminal sugar binding domains. Thus, it is clear that periplasmic sugar receptors and cytoplasmic sugar repressors are derived from a common ancestor.…”

Evolutionary relationships between sugar kinases and transcriptional repressors in bacteria

“…Keywords : transcription, repressors, sugar kinases, phylogenetic family, evolution we reported that a large family of including LacI, GalR and FruR is class of bacterial periplasmic sugar- (Vartak e t al., 1991 ;Tam & Saier, 1993a). These proteins are homologous only in their Ctermina I, sugar-binding regions, and the receptor proteins lack the N-terminal DNA-binding domains that contain identifi'ible helix-turn-helix motifs (Vartak e t al., 1991 ;Weickt t-t & Adhya, 1992).…”