分子生物學(xué)-05真核轉(zhuǎn)錄-wenkub
2024-10-25 07 本頁(yè)面
【正文】 TFIIIB functions as a positioning factor, responsible for localizing RNA polymerase correctly. Like SL1 at the pol I promoter, it resembles a sigma factor.,Promoter structure of RNA polymerase II,One upstream promoter, with relatively fixed location. TATA box: ~25 bp upstream, 8 bp consensus sequence consists entirely of AT. The TATA box tends to be surrounded by GCrich sequences. It is almost identical with the 10 sequence found in bacterial promoters. The minority of promoters that do not contain a TATA element are called TATAless promoters.,TBP: TATAbinding protein, ~30 kD. TAFs: for TBPassociated factors.,The assembles at the promoter,Promoters for RNA polymerase II have short sequence elements,CAAT box : 75, CAAT. a common elements, functions in either orientation. To increases promoter strength. GC box:90, GGGCGG. Often multiple copies. in either orientation. a relatively common promoter component.,Promoters for RNA polymerase II have short sequence elements,Promoters for RNA polymerase II have short sequence elements,3. Enhancer,bidirectional elements that assist initiation function in either orientation and in any location (upstream or downstream) relative to the promoter,An enhancer in the virus SV40 It contains two identical sequences of 72 bp each, repeat
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1