title: TF1, the bacteriophage SPO1-encoded type II DNA-binding protein, is essential for viral multiplication.
abstract: The lytic Bacillus subtilis bacteriophage SPO1 encodes an abundant, 99-amino-acid type II DNA-binding protein, transcription factor 1 (TF1). TF1 is special in this family of procaryotic chromatin-forming proteins in its preference for hydroxymethyluracil-containing DNA, such as SPO1 DNA, and in binding with high affinity to specific sites in the SPO1 chromosome. We constructed recessive null alleles of the TF1 gene and introduced them into SPO1 chromosomes. Segregation analysis with partially diploid phage heterozygous for TF1 showed that phage bearing only these null alleles was inviable. Deletion of the nine C-proximal amino acids of TF1 prohibited phage multiplication in vivo and abolished its site-specific DNA-binding activity in vitro.
authors.affiliation: Department of Biology, University of California, San Diego, La Jolla 92093.
authors.forename: M H
authors.initials: MH
authors.lastname: Sayre
authors.forename: E P
authors.initials: EP
authors.lastname: Geiduschek
mesh_terms: D000483:Alleles; D001412:Bacillus subtilis; D001435:Bacteriophages / Q000235:genetics* / Q000254:growth & development; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005822:Genetic Vectors; D009154:Mutation; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism / Q000502:physiology
chemical_list: D004279:DNA, Viral; D004268:DNA-Binding Proteins; D014157:Transcription Factors; D004262:DNA Restriction Enzymes