Intiation:

1. Occurs in the nucleus

2. Three different RNA Polymerase: RNA polymerase I (transcribes rRNA), RNA polymerase II (transcribes mRNA), and RNA polymerase III (transcribes tRNA). (1NIK)

3.TFIID has similar functions as sigma factor but binds to the TATA box at -35.

4. RNA Polymerase II contains TFIID,E,A,B,H, and F called the initiation complex with other enhancers and mediators.

5. Promoter regions are different and has more protomers. The TATA box (-35 or -100), CAAT, and the GC rich region.

6. Alpha2 subunit has a combination activity as TFIIF and TFIIA (binding to non-tamplate DNA and RNA Polymerase II.

Initiation:

1. Occurs in the cytoplasm

2. RNA Polymerase core enzyme: alpha 2, beta, and beta prime subunits.

3. Sigma Factor (1SIG): use for identification of promoter (start site), involve in RNA synthesis, and disassociates after initiation complex is form.

4. RNA Polymerase Holoenzyme (2CWO): contains the core enzyme with the sigma factor.

5. Promoter: Contains the TATA Box (-10) and the -35 regions

6. Alpha2 subunit binds the UP elements and the RNA Polymerase.

1. Transcription elogation occurs in the nucleus while translation occurs in the cytoplasm

2. Has a variation of topoisomerase activity.

3. RNA modification with the addition of the 7-N methylated GTP at the 5' end

4. Elongation factors s TFIIS, TFIIF, human elongin, human 11-19 lysine-rich leukemia (ELL) mediate elongation [17].

1. Hairpin loop structure aids in termination (1HS1)

2.Rho dependent termination: requiring the Rho protien to cleave the RNA (1A62 Rho binding domain)

3. Rho Independent : utilitzing hairpin loops caused by inverted repeats of A-T rich regions which weakens and RNA dissociates

1. Poly A tail signal aids in termination

2. RNA Polymerase II CTD promotes/mediates cleavage of RNA

3. Endo/exo- nuclease cleaves off RNA

4. Addition of the Poly A tail after cleavage

1. Lost of sigma factor: allowing for RNA Polymerase core enzyme to bind stronger to the DNA template (1S77 RNA Polymerase during elongation) [13]

2. Can couple transcription and translation in the cytoplasm

3. Topoisomerase: There are two types which play a role in causing negative supercoiling. Type 1: catalyzes the cleavage and resealing of one sided nicked DNA. Type 2: catalyzes the cleavage of double stranded nicks (Gyrase)

4. The two major elongation factors that play a role is the Nus (N utiliziation substance) and Gre factors. There are several subtypes of Nus (2ASB) such as NusA which plays a role in antitermination and pausing while NusG increases elongation rates and NusB and NusE are responsible exclusively to rRNA synthesis. Gre factors suppresses elongation arrest thus increasing elongation efficienccy during mRNA synthesis. In addition, Gre factors enhances the fidelity of transcription by excising misincorporated nucleotides [14][15].