Requirement for an A-tract structure at the binding site of phage phi 29 transcriptional activator.
The Bacillus subtilis phage phi 29 transcriptional activator, protein p4, binds to the 5'-AACT-TTTT-15 base-pair spacer-AAAATGTT-3' inverted repeat. In this communication, we study the influence in protein p4 binding of the DNA helical structure within the protein p4 recognition sequences, 5'-AAAATAG-3'. Protein p4 could efficiently bind to a modified target in which the A-tracts had been changed into T-tracts (a different sequence with a similar structure). Binding was lost when the structure of the binding site was modified by an interrupting C residue. The results suggest that the DNA helical structure of the A-tracts is critical for p4 binding. Two models are described that would explain how protein p4 recognized its target sequences on the DNA.
Nuez
B
B
Centro de Biología Molecular, Severo Ochoa, (CSIC-UAM), Universidad Autónoma, Cantoblanco, Madrid, Spain.
Rojo
F
F
Salas
M
M
D017103:Bacillus Phages / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation
D015534:Trans-Activators