RNA polymerase II terminates after a short distance; small oligonucleotides of 4–5 nt are unstable; crystal structures of these RNA/DNA hybrids are unordered. Only longer hybrids have proper base pairing. The short RNA products are degraded rapidly. The suggestion is that this abortive initiation is a form of promoter proofreading.

TLS Online TPP Program

#Id: 10094

#Unit 4. Cell Communication and Cell Signaling

Activation of integrins involves:

Conformational changes near the propeller and 

 βA domains

Separation of the transmembrane and cytoplasmic domains

TLS Online TPP Program

#Id: 9694

#Unit 4. Cell Communication and Cell Signaling

Phosphorylation causes the binding of AS160 to the 

14-3-3 protein that sequesters it in the cytosol away from its target Rab proteins

TLS Online TPP Program

#Id: 2735

#Unit 13. Methods in Biology

In Run-on transcription- the RNA polymerase that has already initiated transcription in vivo simply “runs on” or continues to elongate the same RNA chains. 

TLS Online TPP Program

#Id: 10512

#Unit 4. Cell Communication and Cell Signaling

EGL-1 protein binds to CED-9, alters its conformation, and catalyzes the release of CED-4 from CED-9

TLS Online TPP Program

#Id: 2649

#Unit 7. System Physiology – Animal

Thin descending and thin ascending segments, have thin epithelial membranes with no brush borders, few mitochondria, & minimal levels of metabolic activity.