Nucleotide sequence of a major class-III phage-T3 RNA-polymerase promoter located at 98.0% of phage-T3 genetic map

Probir Sarkar, Dola Sengupta, Shantanu Basu, Umadas Maitra

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The entire nucleotide sequence of a 409-bp HincII fragment, located within the MboI-E fragment on bacteriophage T3 DNA and containing a major class-III T3 RNA polymerase promoter positioned at 98% on the standard T3 genetic map, has been determined. Alignment of this class-III promoter with previously determined T3 RNA polymerase promoters, with start points of transcription (+1) in register, indicates high degree of sequence conservation between position -16 to +6 among all T3 RNA polymerase promoters. The conserved portion of the (-) strand sequence is 5'-A-AT-T-TA-A-C-C-C-T-C-A-C-T-A-A-A-G-G-G-A---3'. This fragment also contains an open reading frame (ORF) with a translational start codon located at position +146 which is preceded by a potential ribosome binding site (RBS). There is more than 70% amino acidsequence homology between the deduced sequences of the -NH2 terminal region of this putative T3 phage protein and the corresponding protein coded by bacteriophage T7 (protein of T7 gene 19.5).

Original languageEnglish (US)
Pages (from-to)351-355
Number of pages5
Issue number3
Publication statusPublished - 1985



  • M13 vector
  • Restriction fragment
  • bacteriophages T3 and T7
  • sequencing
  • transcriptional start points

ASJC Scopus subject areas

  • Genetics

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