Question

Describe the allosteric regulation model for transcription termination and briefly indicate how this model can explain both Rho dependent and Rho independent termination reactions.

Answer 1

Allosteric model of intrinsic termination is basically a detailed set of confirmation changes in combination with hairpin invasion. In this case of hairpin invasion mechanism, the terminator hairpin is proposed to dissociate the EC and the DNA 3' end remains there in the active site by sweeping across the main cleft, disrupting EC stabilizing contact and causing TC folding.

Rho factor is a type of proteins found in prokaryotes. It is found to be involved in transcription termination. There are two types of transcription termination which are found in prokaryotes.

Rho dependent and rho independent

Rho independent termination is also known as intrinsic termination. Rho dependent terminators account for almost half of the e. Coli factor dependent terminators. Also rho dependent terminators were first identified in genomes of bacteriophage. Rho independent termination leads to release of newly made rna by stopping rna transcription.

Rho dependent termination generally occurs when rho proteins dissassembles the rna polymerase and moves it off of the template.