Wild-type U 1 RNA and 1 28 pre-mRNA 22.4 The spliceosome Normal splicing contains SnRNas 6 exon INtron 3 adenovirus splice site igure 22.9 wild-type U1 sn RNA and mutant 125 pre-mRNA Mutations that No splicing abolish function of thes￠ splicing site exon GU G AA U intron 31 can be suppressed by mutant splice site compensating Mutant 1 snRNA and mutant 1 2S RNA Splicing restored mutations in U1 snrna that restore ba ase pairin g U^5 6 exon GU GAAUintron 3 消当
Figure 22.9 Mutations that abolish function of the 5￠ splicing site can be suppressed by compensating mutations in U1 snRNA that restore base pairing. 22.4 The spliceosome contains snRNAs
Ex Intron E XOn 22. 4 The JACUAAC- Py-AG. Left Branch Pytract Right consensus consensus spliceosome AS F/F2 contains snrNas U binds 5 spice site ATP hydrolyzed u2AF binds pyrimidine tra d Figure 22. 10 The ●AsF2- UACU AA Py-AG→ com ple 2 binds branch site splicing reaction OU2AF proceeds through 日 complex L5]4/6 tri mer binds 5 binds exonat 5 ste discrete stages in L6 binds U2 which spliceosome U6 B2 complex sed formation involves at 5'splce site ATP hydrolyzed the interaction of UACUAAC P U4 is released components that U6/2 catty zes transeserifi catio ATP hydrolyzed U5 binds exon at 3 splice site site cleaved lariat for me recognIze the consensus UACUA U2/5/6 rem ain boundto lariat 3 site cleaved exonsligated sequences U UACUAAC--Py-AG Spliced RNA, is released 请莘大 Lariat debranched
Figure 22.10 The splicing reaction proceeds through discrete stages in which spliceosome formation involves the interaction of components that recognize the consensus sequences. 22.4 The spliceosome contains snRNAs