Clamp-loading complex

Venclovas, C., Thelen, M. P. (2000). Structure-based predictions of RADI, RAD9, HUSl and RAD17 participation in sliding clamp and clamp-loading complexes. Nucleic Acids Research, 28, 2481-2493. 

DNA polymerase III is an asymmetric dimer. It contains two copies of the core polymerase, snbnnits a, e, and 0. The a subunit has polymerase activity while e is a 3 — 5 proofreading exonuclease. A 2 subunit is associated with one arm and a (55 i/)2 subunit with the other. These serve as the clamp-loading complex. The P2 subunits form ringlike structures that serve as sliding DNA clamps. 

Family C of DNA polymerases is presented exceptionally by bacterial enzymes involved in replicative processes. So, the DNA polymerase III holoenzyme is the main enzyme realizing the DNA replication in Escherichia coli. Bacillus subtilis, and belongs to family C polymerases. It consists of three assemblies the pol 111 core, the beta sliding clamp processivity factor and the clamp-loading complex. The core consists of three subunits—a, the polymerase activity hub, 8, exonucleolytic proofreader, and 0, which may act as a stabilizer for e. The holoenzyme contains two cores, one for each strand, the lagging and leading [19]. The beta shding clamp processivity factor is also present in duplicate, one for each core, to create a clamp... 

The y-complex clamp-loader is a heteropentameric ATPase responsible for assembling p onto DNA at primed sites (26-28). The clamp loading process is illustrated in Fig. 5b. The y-complex binds and opens the ring-shaped P-clamp in the presence of ATP. The ATP-bound y-complex selectively binds to a primed site that stimulates ATP hydrolysis and results in release of the clamp-loader and closure of P around DNA (20). 

Bermudez VP, Lindsey-Boltz LA, Cesare AJ, Maniwa Y, Griffith JD, Hurwitz J, Sancar A. Loading of the human 9-1-1 checkpoint complex onto DNA by the checkpoint clamp loader hRadl7-replication factor C complex in vitro. Proc. Natl. Acad. Sci. U.S.A. 2003 100(4) 1633-1638. 

Bolted joints can be designed in many configurations especially such complex joints as the root ends of helicopter blades, which are usually made from metals. The correct torque loading on bolts is important as the clamping force suppresses transverse tensile stresses and greatly increases the strength of bolted joints. ... 

When the mold has been loaded with preform, it is clamped shut and liquid catalyzed resin is heated and pumped under modest pressure in the mold, saturating the preform and pushing air out through vents. Cycle times vary from 1 to 20 min depending on size and complexity of the part. Weights vary from a few ounces to several hundred pounds. Molds can be made of reinforced plastic for short runs of product or steel for high-volume runs. 

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