The DNA-binding properties of an artificial 42-residue polypeptide derived from a natural repressor.
Bacteriophage 434 repressor recognizes the operator sequences ACAAG and ACAAT. As the same or similar sequences occur in the enhancer region of HIV-1, 434 repressor was a potential HIV enhancer-binding protein. We found that the interaction of the DNA-binding domain of 434 repressor with a 57-bp HIV enhancer DNA was very weak whereas a 42-residue construct, comprising the recognition helix and four copies of a positively charged segment of the repressor, bound strongly. The results of footprint and cell-free in vitro transcription studies showed that the 42-residue peptide bound preferably to the enhancer region of HIV-1 and acted as an artificial repressor. Replacement of an essential glutamine of the recognition helix by glutamic acid resulted in a partial shift of the sequence specificity of the 42-residue peptide.
Hehlgans
T
T
Biochemisches Institut, Universität Zürich, Switzerland.
Stolz
M
M
Klauser
S
S
Cui
T
T
Salgam
P
P
Verca
S B
SB
Widmann
M
M
Leiser
A
A
Städler
K
K
Gutte
B
B
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004742:Enhancer Elements, Genetic; D015967:Gene Expression Regulation, Viral; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics*; D008969:Molecular Sequence Data; D009875:Operator Regions, Genetic; D010455:Peptides / Q000378:metabolism*; D012097:Repressor Proteins / Q000737:chemistry*; D013329:Structure-Activity Relationship; D014157:Transcription Factors; D014764:Viral Proteins / Q000737:chemistry*
C063367:434-repressor protein, Bacteriophage 434; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D010455:Peptides; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins