Promoter Pribnow sequence

Promoter sequences. In 1975, Pribnow pointed out46 that a series of six known promoters had a conserved 7-base sequence beginning six nucleotides upstream from the initiation site for transcription. Although this sequence varies somewhat from one promoter to another, it has been found in hundreds of E. coli promoters. This is called the -10 region, the Pribnow sequence, or Pribnow box (the last in recognition of the fact that people like to draw boxes around these special sequences). A typical 6-base consensus Pribnow sequence is 5-TATAAT as written for the coding strand, whose sequence corresponds to that of the rnRNA. Only three of these bases are highly... 

It is clear from Eq. 28-1 that the efficiency of initiation depends upon both the affinity Kt and the rate constant k for opening of the double helix. Notice that the Pribnow sequence is AT-rich therefore, opening of the helix at this point would be easier than in a GC-rich region. Tlius, the Pribnow sequence may represent a point of entry of RNA polymerase to form the open complex.67 Other upstream A T tracts are often present frequently at about the -43 position in the UP element. They also seem to strengthen promoter activity.68 Tire open complex is thought to undergo some kind of isomerization to form an initial transcribing... 

How does RNA polymerase know where to begin transcription In prokaryotic transcription, RNA polymerase is directed to the gene to be transcribed by the interactions between the polymerase s O-subunit and sequences of DNA near the start site called promoters. Gonsensus sequences have been established for prokaryotic promoters, and the key elements are sequences at —35 and —10, the latter called the Pribnow box. In eukaryotic transcription, RNA polymerase binds to promoters as well, but there is no O-subunit, although there is a specific subunit, RBP4, that is involved in promoter recognition. 

With the help of sigma factor, RNA polymerase recognizes and binds to the promoter region. The bacterial promoter contains two consensus sequences, called the Pribnow box (or TATA box) and the -35 sequence. The promoter identifies the start site for transcription and orients the enzyme on the template strand. The RNA polymerase separates the two strands of DNA as it reads the base sequence of the template strand. 

Initiation of transcription involves binding of the RNA polymerase to the promoter region. This sequence contains characteristic consensus nucleotide sequences that are highly conserved. These include the Pribnow box and the -35 sequence. Elongation involves RNA polymerase copying one strand of the DNA double helix, pairing C s with G s and A s (on the DNA template) with U s on the RNA transcript. Substrates are ribonucleoside triphosphates. Termination may be accomplished by the RNA polymerase alone, or may require p factor. 

RNA polymerase binding sites 5 -TATAATb Bacterial -10 or Pribnow promoter sequence... 

In E. coli precise spacing between the conserved -35 and -10 (Pribnow) promoter elements has been found to be a critical determinant of promoter strength. What does this suggest about the interaction between RNA polymerase and these conserved sequences in the DNA ... 

Fig. 17-1 Pribnow box sequences from a number of promoters in bacteria. The regions of homology are underlined.

No. The Pribnow box is only part of the sequence that defines the promoter. It corresponds to the -10 bp region of 7 nucleotides. There is another region centered around the -35 bp position that is an essential part of the promoter. 

Pribnow box a DNA base sequence that is part of a prokaryotic promoter it is located 10 bases before the transcription start site (11.2)... 

Pribnow box A consensus sequence of nucleotides - TATAAT - occurring in the promoter region of prokaryote genes see operon) about 10 nucleotides before the start of transcription. The predominance of adenine and thymine bases means that hydrogen bonding between the two DNA strands in this region is relatively weak, enabling the strands to be separated more easily to permit transcription by RNA polymerase. See also TATA box. 

Promoter regions (switch on transcription) Upstream promoter sequence CAAT followed by Core (or Basal) promoter TATA (Hogness box) Sequence TTGACA (-35) followed by TATAAT (-10 or Pribnow box) are upstream of the transcription start (+1)... 

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