BIOMAT Database Logo BIOMAT Database Logo

Amino acids determining operator binding specificity in the helix-turn-helix motif of Tn10 Tet repressor. 1991

A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Lehrstuhl für Mikrobiologie, Friedrich-Alexander Universität Erlangen-Nürnberg, FRG.

Each of 22 amino acids in the proposed alpha-helix-turn-alpha-helix operator binding motif of the Tn10 encoded Tet repressor was replaced by alanine and one residue was replaced by valine to determine their role in tet operator recognition by a 'loss of contact' analysis with 16 operator variants. One class of amino acids consisting of T27 and R28 in the first alpha-helix and L41, Y42, W43 and H44 in the recognition alpha-helix are quantitatively most important for wild-type operator binding. These residues are probably involved in the structural architecture of the motif. A second class of residues is quantitatively less important for binding, but determines specificity by forming base pair specific contacts to three positions in tet operator. This property is most clearly demonstrated for Q38 and P39 and to a lesser extent for T40 at the N-terminus of the recognition alpha-helix. The contacted operator base pairs indicate that the N-terminus of the recognition alpha-helix is located towards the palindromic center in the repressor-operator complex. Although the orientation of the recognition alpha-helix in the Tet repressor-tet operator complex is inversed as compared with the lambda- and 434 repressor-operator complexes, the reduced operator binding of the TA27 mutation in the first alpha-helix suggests that the hydrogen bonding networks connecting the two alpha-helices may be similar in these proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

UI MeSH Term Description Entries
D008969 Molecular Sequence Data Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories. Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009154 Mutation Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations. Mutations
D009875 Operator Regions, Genetic The regulatory elements of an OPERON to which activators or repressors bind thereby effecting the transcription of GENES in the operon. Operator Region,Operator Regions,Operator, Genetic,Genetic Operator,Genetic Operator Region,Genetic Operator Regions,Genetic Operators,Operator Region, Genetic,Operators, Genetic,Region, Genetic Operator,Region, Operator,Regions, Genetic Operator,Regions, Operator
D010957 Plasmids Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS. Episomes,Episome,Plasmid
D011487 Protein Conformation The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain). Conformation, Protein,Conformations, Protein,Protein Conformations
D011815 R Factors A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation. R Factor,R Plasmid,R Plasmids,Resistance Factor,Resistance Factors,Factor, R,Factor, Resistance,Factors, R,Factors, Resistance,Plasmid, R,Plasmids, R
D012097 Repressor Proteins Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release. Repressor Molecules,Transcriptional Silencing Factors,Proteins, Repressor,Silencing Factors, Transcriptional
D004269 DNA, Bacterial Deoxyribonucleic acid that makes up the genetic material of bacteria. Bacterial DNA
D004926 Escherichia coli A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc. Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D000595 Amino Acid Sequence The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION. Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein

Related Publications

A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Functional roles of amino acid residues involved in forming the alpha-helix-turn-alpha-helix operator DNA binding motif of Tet repressor from Tn10.
October 1992, Proteins,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Dominant negative mutations in the Tn10 tet repressor: evidence for use of the conserved helix-turn-helix motif in DNA binding.
September 1985, Proceedings of the National Academy of Sciences of the United States of America,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Tn10 tet operator mutations affecting Tet repressor recognition.
May 1986, Nucleic acids research,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Quantitative analysis of Tn10 Tet repressor binding to a complete set of tet operator mutants.
May 1990, Nucleic acids research,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Lac repressor with the helix-turn-helix motif of lambda cro binds to lac operator.
August 1992, The EMBO journal,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Tn10-encoded tet repressor can regulate an operator-containing plant promoter.
March 1988, Proceedings of the National Academy of Sciences of the United States of America,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Tet repressor binding induced curvature of tet operator DNA.
August 1989, Nucleic acids research,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Purification of the TET repressor and TET operator from the transposon Tn10 and characterization of their interaction.
June 1982, The Journal of biological chemistry,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Noninducible Tet repressor mutations map from the operator binding motif to the C terminus.
February 1993, Journal of bacteriology,
A Wissmann, and R Baumeister, and G Müller, and B Hecht, and V Helbl, and K Pfleiderer, and W Hillen
Saturation mutagenesis of the Tn10-encoded tet operator O1. Identification of base-pairs involved in Tet repressor recognition.
August 1988, Journal of molecular biology,
Copied contents to your clipboard!