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1scu
From Proteopedia
(New page: 200px<br /><applet load="1scu" size="450" color="white" frame="true" align="right" spinBox="true" caption="1scu, resolution 2.5Å" /> '''THE CRYSTAL STRUCTURE...) |
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| - | [[Image:1scu.gif|left|200px]]<br /><applet load="1scu" size=" | + | [[Image:1scu.gif|left|200px]]<br /><applet load="1scu" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1scu, resolution 2.5Å" /> | caption="1scu, resolution 2.5Å" /> | ||
'''THE CRYSTAL STRUCTURE OF SUCCINYL-COA SYNTHETASE FROM ESCHERICHIA COLI AT 2.5 ANGSTROMS RESOLUTION'''<br /> | '''THE CRYSTAL STRUCTURE OF SUCCINYL-COA SYNTHETASE FROM ESCHERICHIA COLI AT 2.5 ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The x-ray crystal structure of succinyl-CoA synthetase (SCS) from | + | The x-ray crystal structure of succinyl-CoA synthetase (SCS) from Escherichia coli has been determined by the method of multiple isomorphous replacement to a resolution of 2.5 A. Crystals of SCS are tetragonal with a space group of P4(3)22 and unit cell dimensions of a = b = 98.47 A and c = 400.6 A. One molecule of SCS (142 kDa) is contained in the asymmetric unit. The current model has been refined to a conventional R factor of 21.6% with root mean square deviations from ideal stereochemistry of 0.022 A for bond lengths and 3.25 degrees for bond angles. The quaternary organization of the E. coli enzyme is an alpha 2 beta 2 heterotetramer. In this tetramer, the alpha-subunits interact only with the beta-subunits, whereas the beta-subunits interact to form the dimer of alpha beta-dimers. The two active site pockets are located at regions of contact between alpha- and beta-subunits. One molecule of coenzyme A is bound to each alpha-subunit at a typical nucleotide-binding motif, and His-246 of each alpha-subunit is phosphorylated. This phosphohistidine, a catalytic intermediate, is stabilized by two helix dipoles (the "power" helices), one from each of the two subunit types. A short segment of the beta-subunit from one alpha beta-dimer is in close proximity to the CoA-binding site of the other alpha beta-dimer, providing a possible rationale for the overall tetrameric structure. |
==About this Structure== | ==About this Structure== | ||
| - | 1SCU is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with COA and PHS as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Succinate--CoA_ligase_(ADP-forming) Succinate--CoA ligase (ADP-forming)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.2.1.5 6.2.1.5] Full crystallographic information is available from [http:// | + | 1SCU is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=COA:'>COA</scene> and <scene name='pdbligand=PHS:'>PHS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Succinate--CoA_ligase_(ADP-forming) Succinate--CoA ligase (ADP-forming)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.2.1.5 6.2.1.5] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SCU OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Succinate--CoA ligase (ADP-forming)]] | [[Category: Succinate--CoA ligase (ADP-forming)]] | ||
| - | [[Category: Bridger, W | + | [[Category: Bridger, W A.]] |
| - | [[Category: Fraser, M | + | [[Category: Fraser, M E.]] |
| - | [[Category: James, M | + | [[Category: James, M N.G.]] |
| - | [[Category: Wolodko, W | + | [[Category: Wolodko, W T.]] |
[[Category: COA]] | [[Category: COA]] | ||
[[Category: PHS]] | [[Category: PHS]] | ||
[[Category: ligase (atp-binding)]] | [[Category: ligase (atp-binding)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:00:11 2008'' |
Revision as of 13:00, 21 February 2008
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THE CRYSTAL STRUCTURE OF SUCCINYL-COA SYNTHETASE FROM ESCHERICHIA COLI AT 2.5 ANGSTROMS RESOLUTION
Overview
The x-ray crystal structure of succinyl-CoA synthetase (SCS) from Escherichia coli has been determined by the method of multiple isomorphous replacement to a resolution of 2.5 A. Crystals of SCS are tetragonal with a space group of P4(3)22 and unit cell dimensions of a = b = 98.47 A and c = 400.6 A. One molecule of SCS (142 kDa) is contained in the asymmetric unit. The current model has been refined to a conventional R factor of 21.6% with root mean square deviations from ideal stereochemistry of 0.022 A for bond lengths and 3.25 degrees for bond angles. The quaternary organization of the E. coli enzyme is an alpha 2 beta 2 heterotetramer. In this tetramer, the alpha-subunits interact only with the beta-subunits, whereas the beta-subunits interact to form the dimer of alpha beta-dimers. The two active site pockets are located at regions of contact between alpha- and beta-subunits. One molecule of coenzyme A is bound to each alpha-subunit at a typical nucleotide-binding motif, and His-246 of each alpha-subunit is phosphorylated. This phosphohistidine, a catalytic intermediate, is stabilized by two helix dipoles (the "power" helices), one from each of the two subunit types. A short segment of the beta-subunit from one alpha beta-dimer is in close proximity to the CoA-binding site of the other alpha beta-dimer, providing a possible rationale for the overall tetrameric structure.
About this Structure
1SCU is a Protein complex structure of sequences from Escherichia coli with and as ligands. Active as Succinate--CoA ligase (ADP-forming), with EC number 6.2.1.5 Full crystallographic information is available from OCA.
Reference
The crystal structure of succinyl-CoA synthetase from Escherichia coli at 2.5-A resolution., Wolodko WT, Fraser ME, James MN, Bridger WA, J Biol Chem. 1994 Apr 8;269(14):10883-90. PMID:8144675
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