BSC 2010 Lecture Notes - Lecture 10: Rna Splicing, Nonsense Mutation, Start Codon

• School: University of Florida
• Department: Biology - Biological Sciences
• Course: BSC 2010
• Professor: Cuddy Katrina

Document Summary

Rna splicing removes introns and splices exons together. Consensus sequences are short sequences between exons and introns; they are first bound by snrnps small nuclear ribonucleoprotein particles. Then other proteins accumulate to form a large rna protein complex called a spliceosome. The complex cuts the pre-mrna, releases the introns, and joins the exons together to produce mature mrna. Figure 10. 9 the spliceosome: an rna splicing machine. In the disease beta thalassemia, a mutation at an intron consensus sequence in the -globin gene prevents the pre-mrna from being spliced correctly. Nonfunctional -globin mrna is produced, resulting in severe anemia. This is an example of how mutations are used to elucidate cause-and-effect relationships. Concept 10. 2 dna expression begins with its transcription to rna. The pre-mrna is also modified at both ends: A 5 cap (cid:894)g (cid:272)ap(cid:895) is added to the 5 e(cid:374)d. it fa(cid:272)ilitates (cid:271)i(cid:374)di(cid:374)g to a ri(cid:271)oso(cid:373)e a(cid:374)d pre(cid:448)e(cid:374)ts digestion by ribonucleases.