1jyl
From Proteopedia
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|PDB= 1jyl |SIZE=350|CAPTION= <scene name='initialview01'>1jyl</scene>, resolution 2.4Å | |PDB= 1jyl |SIZE=350|CAPTION= <scene name='initialview01'>1jyl</scene>, resolution 2.4Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene> and <scene name='pdbligand=CDC:[2-CYTIDYLATE-O | + | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene> and <scene name='pdbligand=CDC:[2-CYTIDYLATE-O'-PHOSPHONYLOXYL]-ETHYL-TRIMETHYL-AMMONIUM'>CDC</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= LicC ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1313 Streptococcus pneumoniae]) | |GENE= LicC ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1313 Streptococcus pneumoniae]) | ||
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[[Category: licc]] | [[Category: licc]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 23 12:24:56 2008'' |
Revision as of 10:24, 23 March 2008
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| , resolution 2.4Å | |||||||
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| Ligands: | and | ||||||
| Gene: | LicC (Streptococcus pneumoniae) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Catalytic Mechanism of CTP:phosphocholine Cytidylytransferase from Streptococcus pneumoniae (LicC)
Overview
Pneumococcal LicC is a member of the nucleoside triphosphate transferase superfamily and catalyzes the transfer of a cytidine monophosphate from CTP to phosphocholine to form CDP-choline. The structures of apo-LicC and the LicC-CDP-choline-Mg(2+) ternary complex were determined, and the comparison of these structures reveals a significant conformational change driven by the multivalent coordination of Mg(2+). The key event is breaking the Glu(216)-Arg(129) salt bridge, which triggers the coalescence of four individual beta-strands into two extended beta-sheets. These movements reorient the side chains of Trp(136) and Tyr(190) for the optimal binding and alignment of the phosphocholine moiety. Consistent with these conformational changes, LicC operates via a compulsory ordered kinetic mechanism. The structures explain the substrate specificity of LicC for CTP and phosphocholine and implicate a direct role for Mg(2+) in aligning phosphocholine for in-line nucleophilic attack and stabilizing the negative charge that develops in the pentacoordinate transition state. These results provide a structural basis for assigning a specific role for magnesium in the catalytic mechanism of pneumococcal LicC.
About this Structure
1JYL is a Single protein structure of sequence from Streptococcus pneumoniae. Full crystallographic information is available from OCA.
Reference
Structure and mechanism of CTP:phosphocholine cytidylyltransferase (LicC) from Streptococcus pneumoniae., Kwak BY, Zhang YM, Yun M, Heath RJ, Rock CO, Jackowski S, Park HW, J Biol Chem. 2002 Feb 8;277(6):4343-50. Epub 2001 Nov 12. PMID:11706035
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