Structural view of the clamp-loading mechanism onto DNA
نویسندگان
چکیده
منابع مشابه
Loading Dynamics of a Sliding DNA Clamp**
Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7...
متن کاملThe internal workings of a DNA polymerase clamp-loading machine.
Replicative DNA polymerases are multiprotein machines that are tethered to DNA during chain extension by sliding clamp proteins. The clamps are designed to encircle DNA completely, and they are manipulated rapidly onto DNA by the ATP-dependent activity of a clamp loader. We outline the detailed mechanism of gamma complex, a five-protein clamp loader that is part of the Escherichia coli replicas...
متن کاملOpening of a monomer-monomer interface of the trimeric bacteriophage T4-coded GP45 sliding clamp is required for clamp loading onto DNA.
The replication system of bacteriophage T4 uses a trimeric ring-shaped processivity clamp (gp45) to tether the replication polymerase (gp43) to the template-primer DNA. This ring is placed onto the DNA by an ATPase-driven clamp-loading complex (gp44/62) where it then transfers, in closed form, to the polymerase. It generally has been assumed that one of the functions of the loading machinery is...
متن کاملMechanism of the Sliding @ - Clamp of DNA Polymerase I 11
DNA polymerase I11 holoenzyme (holoenzyme), the multiprotein replicase of Escherichia coli, is essentially unlimited in processive DNA synthesis. Processive activity can be reconstituted from two components. One component, the @ preinitiation complex, is a @ dimer clamped onto primed DNA. The @ preinitiation complex is formed by the five-protein y complex, which hydrolyzes ATP to chaperone @ on...
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ژورنال
عنوان ژورنال: Acta Crystallographica Section A Foundations of Crystallography
سال: 2005
ISSN: 0108-7673
DOI: 10.1107/s0108767305095802