In C. elegans, about 70% of genes are processed by the trans-splicing mechanism

TLS Online TPP Program

#Id: 2307

#Unit 3. Fundamental Processes

During the transition to the open complex, the conformation of both the RNA polymerase and the DNA change. 

1) 90° bend in the DNA, which allows the template strand to approach the active site of the enzyme; 

2) strand opening of the promoter DNA between -11 and +3 with respect to the transcription start site; 

3) the promoter DNA scrunches into the active channel forming the transcription bubble; and 

4) closing of the jaws of the enzyme to encircle the section of the promoter downstream section of the transcription start site.

TLS Online TPP Program

#Id: 2308

#Unit 3. Fundamental Processes

Sigma factor contacts the promoter directly at both the -35 and -10 consensus sequences was provided by substitutions in the sigma factor that suppressed mutations in the consensus sequences.

TLS Online TPP Program

#Id: 2309

#Unit 3. Fundamental Processes

Comparisons of the sequences of several bacterial sigma factors suggested conserved regions in E. coli s70  that interact directly with promoters DNA-binding regions of the sigma factor fold into independent domains in the protein regions 1.2, 2.3– 2.4, 3.0, and 4.1–4.2.

TLS Online TPP Program

#Id: 2310

#Unit 3. Fundamental Processes

The transition from the closed to the open complex involves structural changes in the enzyme and the opening of the DNA double helix to reveal the template and nontemplate strands. This “melting” occurs between positions –11 and +2, with respect to the transcription start site.

TLS Online TPP Program

#Id: 2311

#Unit 3. Fundamental Processes

P-TEFb activates elongation, splicing and polyadenylation and phosphorylates

  Serine 2 CTD

  TAT-SF1

  SPT5

TLS Online TPP Program

#Id: 2312

#Unit 3. Fundamental Processes

Ser2 phosphatase Fcp1 regenerates RNA Pol II pool