TLS Online TPP Program

#Id: 6288

#Unit 3. Fundamental Processes

A consensus sequence is, in each case a version of the sequence having at each position the nucleotide (or amino acid) most commonly found there in different examples. Thus, the consensus sequence for promoters in E. coli recognized by RNA polymerase containing s70

TLS Online TPP Program

#Id: 6289

#Unit 3. Fundamental Processes

This consensus sequence was derived by aligning 300 sequences known to function as s70 promoters and ascertaining the most common base found at each position in the –35 and –10 hexamers. That nucleotide is then chosen as the nucleotide of choice at that position in the consensus; its relative frequency and the frequencies with which the other three nucleotides occur at each position are portrayed in the graph. 

Note that there is no significant consensus among the 17–19 nucleotides that lie in the region between –35 and –10.

TLS Online TPP Program

#Id: 6290

#Unit 3. Fundamental Processes

Consensus Sequences

TLS Online TPP Program

#Id: 6291

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 6292

#Unit 3. Fundamental Processes

The carboxy-terminal domain of the a subunit (aCTD) recognizes the Up-element (where present), whereas s regions 2 and 4 recognize the –10 and –35 regions

TLS Online TPP Program

#Id: 6294

#Unit 3. Fundamental Processes

In holoenzyme Region 1.1 of s is highly negatively charged hence region 1.1 acts as a molecular mimic of DNA