1os1
From Proteopedia
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|PDB= 1os1 |SIZE=350|CAPTION= <scene name='initialview01'>1os1</scene>, resolution 1.8Å | |PDB= 1os1 |SIZE=350|CAPTION= <scene name='initialview01'>1os1</scene>, resolution 1.8Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=ATP:ADENOSINE-5'-TRIPHOSPHATE'>ATP</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PYR:PYRUVIC+ACID'>PYR</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Phosphoenolpyruvate_carboxykinase_(ATP) Phosphoenolpyruvate carboxykinase (ATP)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.49 4.1.1.49] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Phosphoenolpyruvate_carboxykinase_(ATP) Phosphoenolpyruvate carboxykinase (ATP)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.49 4.1.1.49] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1oen|1OEN]], [[1aq2|1AQ2]], [[1ayl|1AYL]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1os1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1os1 OCA], [http://www.ebi.ac.uk/pdbsum/1os1 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1os1 RCSB]</span> | ||
}} | }} | ||
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[[Category: Sudom, A.]] | [[Category: Sudom, A.]] | ||
[[Category: Walters, R.]] | [[Category: Walters, R.]] | ||
| - | [[Category: ATP]] | ||
| - | [[Category: CA]] | ||
| - | [[Category: MG]] | ||
| - | [[Category: PYR]] | ||
| - | [[Category: activation]] | ||
| - | [[Category: calcium]] | ||
[[Category: enzyme mechanism]] | [[Category: enzyme mechanism]] | ||
| - | [[Category: phosphotransfer]] | + | [[Category: phosphotransfer,calcium,activation]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:49:32 2008'' |
Revision as of 19:49, 30 March 2008
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| , resolution 1.8Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , | ||||||
| Activity: | Phosphoenolpyruvate carboxykinase (ATP), with EC number 4.1.1.49 | ||||||
| Related: | 1OEN, 1AQ2, 1AYL
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of Phosphoenolpyruvate Carboxykinase complexed with ATP,Mg, Ca and pyruvate.
Overview
The 1.8-A resolution structure of the ATP-Mg(2+)-Ca(2+)-pyruvate quinary complex of Escherichia coli phosphoenolpyruvate carboxykinase (PCK) is isomorphous to the published complex ATP-Mg(2+)-Mn(2+)-pyruvate-PCK, except for the Ca(2+) and Mn(2+) binding sites. Ca(2+) was formerly implicated as a possible allosteric regulator of PCK, binding at the active site and at a surface activating site (Glu508 and Glu511). This report found that Ca(2+) bound only at the active site, indicating that there is likely no surface allosteric site. (45)Ca(2+) bound to PCK with a K(d) of 85 micro M and n of 0.92. Glu508Gln Glu511Gln mutant PCK had normal activation by Ca(2+). Separate roles of Mg(2+), which binds the nucleotide, and Ca(2+), which bridges the nucleotide and the anionic substrate, are implied, and the catalytic mechanism of PCK is better explained by studies of the Ca(2+)-bound structure. Partial trypsin digestion abolishes Ca(2+) activation (desensitizes PCK). N-terminal sequencing identified sensitive sites, i.e., Arg2 and Arg396. Arg2Ser, Arg396Ser, and Arg2Ser Arg396Ser (double mutant) PCKs altered the kinetics of desensitization. C-terminal residues 397 to 540 were removed by trypsin when wild-type PCK was completely desensitized. Phe409 and Phe413 interact with residues in the Ca(2+) binding site, probably stabilizing the C terminus. Phe409Ala, DeltaPhe409, Phe413Ala, Delta397-521 (deletion of residues 397 to 521), Arg396(TAA) (stop codon), and Asp269Glu (Ca(2+) site) mutations failed to desensitize PCK and, with the exception of Phe409Ala, appeared to have defects in the synthesis or assembly of PCK, suggesting that the structure of the C-terminal domain is important in these processes.
About this Structure
1OS1 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Mechanisms of activation of phosphoenolpyruvate carboxykinase from Escherichia coli by Ca2+ and of desensitization by trypsin., Sudom A, Walters R, Pastushok L, Goldie D, Prasad L, Delbaere LT, Goldie H, J Bacteriol. 2003 Jul;185(14):4233-42. PMID:12837799
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