BIOL3150 Lecture Notes - Operon, Helicase, Ribosomal Rna
Document Summary
Chapter 12: because prokaryotes lack nuclei, transcription and translation can occur simultaneously. Allows for attenuation to control transcription of trp operon and terminate transcription at operon. Formation of shorter loop stimulates rho-independent termination of transcription. Stalled rna polymerase by hairpin allows rho helicase enzyme to terminate transcription rho breaks rna-dna base paires: many genetic elements contribute to transcription of eukaryotic gnnes, three distinct rna poly in eukaryotes. Rna poly ii = protein coding genes. Rna poly iii = trna: rna polymerase has low affinity for dna, so recruited by dna-binding protein, different sequence motifs for promoter of each rna poly, rna poly ii = Cpsf association with ctd of rna poly ii allows coupling of polyadenylation w/ transcription termination: introns could be major component of mrna transcript, (ex gu-ag introns)
