Structures of phi29 DNA Polymerase Complexed with Substrate: The Mechanism of Translocation in B-Family Polymerases
Replicative DNA polymerases (DNAPs) move along template DNA in a processive manner. The structural basis of the mechanism of translocation has been better studied in the A-family of polymerases than in the B-family of replicative polymerases. To address this issue, we have determined the X-ray crystal structures of phi29 DNAP, a member of the protein-primed subgroup of the B-family of polymerases, complexed with primer-template DNA in the presence or absence of the incoming nucleoside triphosphate, the pre- and post-translocated states, respectively. Comparison of these structures reveals a mechanism of translocation that appears to be facilitated by the coordinated movement of two conserved tyrosine residues into the insertion site. This differs from the mechanism employed by the A-family polymerases, in which a conserved tyrosine moves into the templating and insertion sites during the translocation step. Polymerases from the two families also interact with downstream single-stranded template DNA in very different ways.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 929955
- Report Number(s):
- BNL-80556-2008-JA; EMJODG; TRN: US200822%%1119
- Journal Information:
- EMBO Journal, Vol. 26; ISSN 0261-4189
- Country of Publication:
- United States
- Language:
- English
Similar Records
The Structure of a High Fidelity DNA Polymerase Bound to a Mismatched Nucleotide Reveals an ;Ajar; Intermediate Conformation in the Nucleotide Selection Mechanism
The Mechanism of the Translocation Step in DNA Replication by DNA Polymerase I: A Computer Simulation Analysis