Biochemistry 2280A Study Guide - Final Guide: Guanine, Methyl Group, Intron
22 Apr 2018
School
Department
Course
Professor
Document Summary
Initiation in eukaryotes differs in several important ways from that in bacteria. Bacteria contain a single type of rna polymerase, eukaryotic cells have 3: rnap 1, These ranp"s are respo(cid:374)si(cid:271)le for tra(cid:374)s(cid:272)ri(cid:271)i(cid:374)g differe(cid:374)t types of genes. Rnap 1 and 3 transcribe the genes encoding trna, rrna and small rnas that play structural and catalytical role in the cell. Rnap2 transcribes the vast majority of the genes in eukaryotes including all those that encode protein. A second difference is that whereas in bacteria rnap (along with its sigma subunit) is able to initiate transcription on its own, eukaryotic rnap requires the assistance of a large set of accessory proteins. Factors, which must assemble at each promoter along with the polymerase before transcription can begin. A third distinctive feature of transcription in euks is that the mechanism that control initiation are much more elaborate than those in prokaryotes.
