title: Location, function, and nucleotide sequence of a promoter for bacteriophage T3 RNA polymerase.
abstract: The major promoters for bacteriophage T3 RNA polymerase on the T3 genome have been mapped by DNA.RNA filter hybridization. One promoter is located in a 300-base-pair Hpa I restriction fragment near the genetic "left" end of T3 DNA. The sequence in the vicinity of the major initiation site of transcription in this region has been determined. A part of the (-)strand sequence is 5' T-A-T-T-T-A-C-C-C-T-C-A-C-T-A-A-A-G-+1 G-G-A-A-U 3'. Comparison of this sequence with the prototype 23-base-pair promoter sequence for bacteriophage T7 RNA polymerase shows a striking pattern of homology and divergence. Between positions -9 and +4, the sequences are virtually identical, whereas between positions -17 and -10, the sequences are quite different. It is postulated that these sequence subsets may perform different functions in transcription initiation by the phage RNA polymerases.
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D009876:Operon; D013604:T-Phages / Q000201:enzymology / Q000235:genetics*; D013698:Templates, Genetic; D014158:Transcription, Genetic
chemical_list: D004279:DNA, Viral; D012321:DNA-Directed RNA Polymerases; D004262:DNA Restriction Enzymes