BIOL 200 Lecture Notes - Lecture 7: Brca1, Dna Profiling, Telangiectasia
Document Summary
(cid:120) pol (cid:631) (cid:396)epla(cid:272)es the rna with dna. (cid:120) dna fragments are then ligated together by dna ligase. Unwinding by large t-antigen (helicase) driven by the hydrolysis of atp. Rpa binds to single-stranded regions: prokaryotic genome = 1 location, eukaryotic genome = many locations, 2 loaded t-antigens, goes in 2 directions. Primer synthesis: primase-pol (cid:272)o(cid:373)ple(cid:454)es s(cid:455)(cid:374)thesize p(cid:396)i(cid:373)e(cid:396) sequences that are base-paired to the parental templates. Pol (cid:632)/rf(cid:272)/pcna (cid:272)o(cid:373)ple(cid:454)es (cid:396)epla(cid:272)e the p(cid:396)i(cid:373)ase-pol complexes and extend the primer sequences: goes in the direction of the replication fork, opposite strand occurs in opposite direction with the other replication fork (leading strands) Further unwinding and binding of rpa to single-stranded regions. Pol (cid:632)/rf(cid:272)/pcna (cid:272)o(cid:373)ple(cid:454)es (cid:272)o(cid:374)ti(cid:374)ue to s(cid:455)(cid:374)thesize the leadi(cid:374)g- strands: the(cid:396)e"s goi(cid:374)g to (cid:271)e a(cid:374) e(cid:454)posed (cid:396)egio(cid:374) that leadi(cid:374)g st(cid:396)a(cid:374)d dna synthesis cannot fill. This requires the lagging strand to fill: re(cid:395)ui(cid:396)es e(cid:454)te(cid:374)sio(cid:374) (cid:271)(cid:455) the (cid:631) (cid:272)o(cid:373)ple(cid:454). Primase-pol (cid:272)o(cid:373)ple(cid:454)es fo(cid:396)(cid:373) p(cid:396)i(cid:373)e(cid:396)s fo(cid:396) laggi(cid:374)g-strand synthesis.
