Sites of phosphorylation on the CTD serve as a recognition or anchor point for other proteins to dock with the polymerase. The capping enzyme (guanylyl transferase), which adds the G residue to the 5' end of newly synthesized mRNA, binds to CTD phosphorylated at serine 5, the first phosphorylation event catalyzed by TFIIH. 

P-TEFb leads to recruitment of a set of proteins called SCAFs to the CTD, and they in turn bind to splicing factors. This may be a means of coordinating transcription and splicing.

TLS Online TPP Program

#Id: 8636

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8991

#Unit 11. Evolution and Behavior

Incomplete lineage sorting (hemiplasy)

If you make a phylogenetic tree of how the alleles are related to each other, it does not mirror how the species split apart.

TLS Online TPP Program

#Id: 1348

#Unit 4. Cell Communication and Cell Signaling

RasD or RasONC  Replacement of the normal glycine 12 with any other amino acid (except proline) “locks” Ras in the active GTP-bound state.

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#Id: 6565

#Unit 7. System Physiology – Animal

TLS Online TPP Program

#Id: 4024

#Unit 2. Cellular Organization

Some regions of chromatin are very densely packed with fibers, displaying a condition comparable to that of the chromosome at mitosis. This material is called heterochromatin.