The internal workings of a DNA polymerase clamp-loading machine
نویسندگان
چکیده
منابع مشابه
The 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 کاملLoading 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 کاملHow a DNA polymerase clamp loader opens a sliding clamp.
Processive chromosomal replication relies on sliding DNA clamps, which are loaded onto DNA by pentameric clamp loader complexes belonging to the AAA+ family of adenosine triphosphatases (ATPases). We present structures for the ATP-bound state of the clamp loader complex from bacteriophage T4, bound to an open clamp and primer-template DNA. The clamp loader traps a spiral conformation of the ope...
متن کاملThe sliding clamp of DNA polymerase III holoenzyme encircles DNA.
DNA polymerases that duplicate chromosomes are remarkably processive multiprotein machines. These replicative polymerases remain in continuous association with the DNA over tens to hundreds of kilobases. What is the chemical basis of their strong grip to the template? The mystery behind the high processivity of the replicative polymerase of the Escherichia coli chromosome, DNA polymerase III ho...
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...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The EMBO Journal
سال: 1999
ISSN: 1460-2075
DOI: 10.1093/emboj/18.3.771