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User:Wally Novak/Sandbox Hicks
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== Structural Highlights == | == Structural Highlights == | ||
| - | <scene name='74/744126/Pcna_monomer_helixfront_2/1'> The PCNA monomers </scene> consist of 258 residues each and are a mass of 28.916 kDa. Each monomer contributes two domains to the trimeric ring. These domains possess anti-parallel beta sheets (blue) which approach each other on one end, but are separated by two alpha helices at the other (red), creating a 45 degree wedge in the sheets with alpha helices at the blunt end. The domains are connected by an extended beta sheet. This creates a <scene name='74/744126/6_fold_symmetry/1'> six-fold symmetry within the trimeric ring </scene> and it also creates a β-α-β-β-β motif going around the ring. <ref>PMID:8001157</ref> | + | <scene name='74/744126/Pcna_monomer_helixfront_2/1'> The PCNA monomers </scene> consist of 258 residues each and are a mass of 28.916 kDa. Each monomer contributes two domains to the trimeric ring. These domains possess anti-parallel beta sheets (blue) which approach each other on one end, but are separated by two alpha helices at the other (red), creating a 45 degree wedge in the sheets with alpha helices at the blunt end. The domains are connected by an extended beta sheet. This creates a <scene name='74/744126/6_fold_symmetry/1'> six-fold symmetry within the trimeric ring </scene> and it also creates a β-α-β-β-β motif going around the ring. <ref>PMID:8001157</ref> |
| - | == | + | == Interactions with DNA == |
| - | + | Other structural features of PCNA elucidate how it functions as a sliding clamp protein, and how PCNA is able to loosely interact with DNA. Firstly, b-DNA and a-DNA have cross sectional diameters of about 18 and 21 Angstroms. PCNA has an internal diameter of approximately 34 Angstroms. [3] The diameter of PCNA being a little less than twice the size of the two most common forms of DNA suggests that size of the clamp plays a role in how tightly it associates with DNA. Specifically, if the difference in diameters was were greater, there would be little association, but if it were smaller, there would be a tighter association, which would not allow for the "sliding" of the sliding clamp. | |
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| + | Another factor that plays a role in association with DNA is the polarity of PCNA. Firstly PCNA also has many <scene name='74/744126/Acidic_residues_pcna/1'> has a relatively large number of acidic residues </scene> giving it a charge of -60. [3] This composition | ||
<ref>doi:10.1006</ref> | <ref>doi:10.1006</ref> | ||
| - | PCNA also has many <scene name='74/744126/Acidic_residues_pcna/1'> | + | <scene name='74/744126/Pcna_with_dna/2'>Text To Be Displayed</scene> |
| + | |||
| + | PCNA also has many <scene name='74/744126/Acidic_residues_pcna/1'>has a large number of acidic residues</scene> | ||
Revision as of 11:20, 11 October 2016
Proliferating Cell Nuclear Antigen
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References
- ↑ PMCID:PMC53402
- ↑ Lee SH, Kwong AD, Pan ZQ, Hurwitz J. Studies on the activator 1 protein complex, an accessory factor for proliferating cell nuclear antigen-dependent DNA polymerase delta. J Biol Chem. 1991 Jan 5;266(1):594-602. PMID:1670772
- ↑ Krishna TS, Kong XP, Gary S, Burgers PM, Kuriyan J. Crystal structure of the eukaryotic DNA polymerase processivity factor PCNA. Cell. 1994 Dec 30;79(7):1233-43. PMID:8001157
- ↑ doi: https://dx.doi.org/10.1006
