MBB 331 Lecture Notes - Lecture 8: Hydrolysis, In Step, Bacteriophage
22 Jul 2020
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Leading strand: 5" 3" synthesis, continuous, in the firection of the fork. How is the clamp opened: atp driven process, 2 beta subunits that clamp around the dna, rapid synth of dna pol iii is because of this clamp. Dna synthesis of e. coli using pol iii: substrate: 5. 4 kb ss c dna genome (single stranded circular) of a phage. Key players: helicase, helix breaker, homohexomer, all the subunits are the same, and there"s 6 of them. Lots of comparisons between species: open helix helicase (separates using atp hydrolysis, prevent reannealing & protect ssdna. Helicase: hexameric ring, homo, bc same subunits, atp being expended to open the ring, 5" 3". In e coli also helps: this also separates dna strands that have just been replicated they become cantomers (interchain linked) Single stranded binding protein to dna: protects the ssdna after its been opened by coating it, also prevents any secondary structure from being formed, homotetramer (4 subunits form 1 coat)
