MCELLBI 110 Lecture Notes - Lecture 5: Hydrolysis, Dna Replication, Dna Gyrase

• School: Berkeley
• Department: Molecular And Cell Biology
• Course: MCELLBI 110
• Professor: Thorner

Document Summary

Lecture #5: dna replication: processivity, progression, and coordination, sliding clamp, c terminus of a subunit makes a major contact, e. coli pol iii (alpha subunit, catalytic) Clamp loader cracks open the sliding clamp ring using the energy of atp binding hydrolysis: the reason an enzyme catalyzes a reaction is because it has highest affinity for transition state. Atp driven staircase arrangement of the subunits in the loader stabilizes the open state of the clamp. Want to stick polymerase where primer is going to be. In the center, triggers hydrolysis of bound atp. Pcna has so many important roles that the dynamics of the loading and unloading of this sliding clamp is controlled by different rfc-like rlc complexes. Many different proteins bind the same site on the pcna, using a pip box motif: each subunit of the pcna homotrimer can serve as binding site for pip box peptides.