A family of bacterial regulators homologous to Gal and Lac repressors.
We describe a family of proteins which regulate transcription of inducible genes in bacteria (GalR-LacI family). An alignment of the proteins in the GalR-LacI family is presented in which these proteins show a very high degree of similarity (60%) throughout the entire sequences. The homology is greatest among the amino-terminal DNA binding domains. Since a portion of the operator sequences occupied by these proteins is also conserved, a similar DNA structure may be required for specific recognition of DNA by members of the GalR-LacI family. Highly conserved motifs involved in effector binding and oligomerization are also identified. This compilation suggests a widespread conservation of these regulators among bacteria, and have strong implications for further study of peptide motifs in domain function, as well as pathways of protein evolution.
Weickert
M J
MJ
Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Adhya
S
S
D000595:Amino Acid Sequence; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D005075:Biological Evolution; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D005690:Galactose / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C050993:Galactose repressor proteins; D012097:Repressor Proteins; D005690:Galactose