On the Solution Structure of the T4 Sliding Clamp (gp45)
- 4 September 2004
- journal article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 43 (40) , 12723-12727
- https://doi.org/10.1021/bi048349c
Abstract
Examination by time-resolved fluorescence spectroscopy of the trimeric bacteriophage T4 clamp protein labeled across its three subunit interfaces with a fluorescence resonance energy transfer (FRET) pair indicates that the clamp exists in just one state in solution, with one open and two closed interfaces. This is in contrast to what is observed in the X-ray crystal structure. The population distribution of the trFRET distance is bimodal, giving 67% as 17 A and 33% as 42 A. This leads to the conclusion that gp45 exists in an asymmetric open state in solution. The further increase in the separation of the FRET pair in the presence of the clamp loader and ATP may be ascribed to either further opening of the open interface or the opening of a closed interface. The ramifications for replisome remodeling by this pathway are discussed.Keywords
This publication has 6 references indexed in Scilit:
- Mechanism of Loading the Escherichia coli DNA Polymerase III Sliding ClampJournal of Biological Chemistry, 2004
- Bacteriophage T4 GenomeMicrobiology and Molecular Biology Reviews, 2003
- Examination of the Role of the Clamp-loader and ATP Hydrolysis in the Formation of the Bacteriophage T4 Polymerase HoloenzymeJournal of Molecular Biology, 2003
- Building a Replisome Solution Structure by Elucidation of Protein-Protein Interactions in the Bacteriophage T4 DNA Polymerase HoloenzymeJournal of Biological Chemistry, 2001
- Crystal structure of the DNA polymerase processivity factor of T4 bacteriophage 1 1Edited by I. A. WilsonJournal of Molecular Biology, 2000
- The internal workings of a DNA polymerase clamp-loading machineThe EMBO Journal, 1999