Phylogenetic, structural and functional analyses of the LacI-GalR family of bacterial transcription factors.
Phylogenetic tree construction for 25 sequenced members of the LacI-GalR family (LGF) of transcription factors revealed that almost all branches are similar in length, radiating essentially from a single point. This observation suggests that most of these proteins arose by duplication events which occurred at a specific time in evolutionary history, and that further duplication events were rare. Analyses of the multiple alignment of the LGF proteins lead to suggestions regarding structure-function relationships and reveal that the helix-turn-helix DNA-binding motif of LGF proteins is similar in sequence to those of numerous non-homologous DNA-binding proteins.
Department of Biology, University of California at San Diego, La Jolla 92093-0116, USA.
C C
CC
Nguyen
M H
MH
Saier
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D029968:Escherichia coli Proteins; D056968:Lac Repressors; D008969:Molecular Sequence Data; D010802:Phylogeny; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C050993:Galactose repressor proteins; D056968:Lac Repressors; D012097:Repressor Proteins; D014157:Transcription Factors