CHM 522 Exam 4 study guide Material verified 100% to enable in acing in your exams

CHM 522 Exam 4 study guide Material verified 100% to enable in acing in your exams Prokaryotic RNAP - Synthesize RNA from DNA antisense (noncoding) strand - template strand sense (coding) - matches the RNA produced prokaryotic gene structure (operon) - single control point for multiple gene products that are transcribed as one unit polycistronic - single mRNA contains multiple translation sites (prokaryotic) monocistronic - single mRNA has only one translation site (eukaryotic) prokaryotic promoter structure - -35 region, -10 AT rich consensus region (Prinbow box) transcription initiation complex prokaryotes - sigma factor binding pulls RNAP to sit down at -9 -- +2 region transcription chain elongation prokaryotes - 1. negative supercoiling before transcription bubble pushes RNAP forward 2. sigma factor remains bound for a long time to allow multiple RNAP to work at once rho-independent termination (prokaryotes) - hairpin forms in transcript by complementary sequences which blocks RNAP from moving, it then falls off Unwinds transcript rho-dependent termination (prokaryotes) - rho factor recognizes specific sequence and serves as helicase. Unwinds RNA-DNA hybrid faster than RNA polymerase can synthesize so enzyme falls off RNAP I - rRNA RNAP II - mRNA RNAP III - 5s RNA, tRNAs, small nuclear and cytoplasmic RNAs RNAP II important components - 1. two Mg2+ 2. Rbp1 subunit 3. Clamp for infinite processivity 4. Proofreading activity phosphorylation of Rbp1 (eukaryotes) - switch initiation to elongation eukaryotic promoter structure - some elements are internal/downstream to gene (+40) GC boxes or TATA boxes upstream of initiation site TATA box - at -27, similar to -10 in bacteria transcription factors in eukaryotes - recognize promoter/enhancer and forms pre-initiation complex (PIC) with RNAP II TFIID - T