2ae9
From Proteopedia
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|SITE= | |SITE= | ||
|LIGAND= | |LIGAND= | ||
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] </span> |
|GENE= holE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |GENE= holE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2ae9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ae9 OCA], [http://www.ebi.ac.uk/pdbsum/2ae9 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2ae9 RCSB]</span> | ||
}} | }} | ||
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[[Category: all helical]] | [[Category: all helical]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 01:51:25 2008'' |
Revision as of 22:51, 30 March 2008
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| Gene: | holE (Escherichia coli) | ||||||
| Activity: | DNA-directed DNA polymerase, with EC number 2.7.7.7 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Solution Structure of the theta subunit of DNA polymerase III from E. coli
Overview
The catalytic core of Escherichia coli DNA polymerase III holoenzyme contains three subunits: alpha, epsilon, and theta. The alpha subunit contains the polymerase, and the epsilon subunit contains the exonucleolytic proofreading function. The small (8-kDa) theta subunit binds only to epsilon. Its function is not well understood, although it was shown to exert a small stabilizing effect on the epsilon proofreading function. In order to help elucidate its function, we undertook a determination of its solution structure. In aqueous solution, theta yielded poor-quality nuclear magnetic resonance spectra, presumably due to conformational exchange and/or protein aggregation. Based on our recently determined structure of the theta homolog from bacteriophage P1, named HOT, we constructed a homology model of theta. This model suggested that the unfavorable behavior of theta might arise from exposed hydrophobic residues, particularly toward the end of alpha-helix 3. In gel filtration studies, theta elutes later than expected, indicating that aggregation is potentially responsible for these problems. To address this issue, we recorded 1H-15N heteronuclear single quantum correlation (HSQC) spectra in water-alcohol mixed solvents and observed substantially improved dispersion and uniformity of peak intensities, facilitating a structural determination under these conditions. The structure of theta in 60/40 (vol/vol) water-methanol is similar to that of HOT but differs significantly from a previously reported theta structure. The new theta structure is expected to provide additional insight into its physiological role and its effect on the epsilon proofreading subunit.
About this Structure
2AE9 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Nuclear magnetic resonance solution structure of the Escherichia coli DNA polymerase III theta subunit., Mueller GA, Kirby TW, DeRose EF, Li D, Schaaper RM, London RE, J Bacteriol. 2005 Oct;187(20):7081-9. PMID:16199579
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