MBIO 3410 Lecture Notes - Lecture 6: Ribosome-Binding Site, Start Codon, Consensus Sequence
24 Dec 2015
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Operons group of gene with related function: linked together, allows for efficient regulation of genes with common function, genes under the control of one promoter and regulator regions, rna polymerase and regulatory proteins. Activators and/or repressors can also bind at/near promoter: have multiple orfs. No organelles transcription and translation can occur. Polycistronic mrna multi-message (several orfs on the same. 5" and 3" utrs regulatory functions, leader sequence, trailer. Shine-dalgarno sequence (ribosome binding site) needed for translation of orf aggagg: consensus sequence upstream of aug start codon simultaneously transcript) Introns are rare sequence: some gram negative bacteria do not have this sequence they have s1 ribosomal protein (cid:1) Rna polymerase holoenzyme: 2 alpha, 1 beta, 1 beta" subunit = core enzyme, sigma factor. For transcription to occur: rna polymerase needs to recognize and bind to promoter, rna polymerase needs to melt dna. Gc rich repetitive area followed by poly-u tail. Chases after rna polymerase and dissociates it from mrna.
