4it9: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
==Structure of Bacterial Enzyme== | |||
=== | <StructureSection load='4it9' size='340' side='right' caption='[[4it9]], [[Resolution|resolution]] 1.70Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4it9]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Synechococcus_sp._pcc_7002 Synechococcus sp. pcc 7002]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IT9 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4IT9 FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4ita|4ita]], [[4itb|4itb]]</td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4it9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4it9 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4it9 RCSB], [http://www.ebi.ac.uk/pdbsum/4it9 PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Succinic semialdehyde dehydrogenase (SSADH) from cyanobacterium Synechococcus differs from other SSADHs in the gamma-aminobutyrate shunt. Synechococcus SSADH (SySSADH) is a TCA cycle enzyme and completes a 2-oxoglutarate dehydrogenase-deficient cyanobacterial TCA cycle through a detour metabolic pathway. SySSADH produces succinate in an NADP(+)-dependent manner with a single cysteine acting as the catalytic residue in the catalytic loop. Crystal structures of SySSADH were determined in their apo form, as a binary complex with NADP(+) and as a ternary complex with succinic semialdehyde and NADPH, providing details about the catalytic mechanism by revealing a covalent adduct of a cofactor with the catalytic cysteine in the binary complex and a proposed thiohemiacetal intermediate in the ternary complex. Further analyses showed that SySSADH is an oxidation-sensitive enzyme and that the formation of the NADP-cysteine adduct is a kinetically preferred event that protects the catalytic cysteine from H2O2-dependent oxidative stress. These structural and functional features of SySSADH provide a molecular basis for cofactor-dependent oxidation protection in 1-Cys SSADH, which is unique relative to other 2-Cys SSADHs employing a redox-dependent formation of a disulfide bridge. | |||
Structural Basis for a Cofactor-dependent Oxidation Protection and Catalysis of Cyanobacterial Succinic Semialdehyde Dehydrogenase.,Park J, Rhee S J Biol Chem. 2013 May 31;288(22):15760-70. doi: 10.1074/jbc.M113.460428. Epub, 2013 Apr 15. PMID:23589281<ref>PMID:23589281</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
==See Also== | |||
*[[Succinate-semialdehyde dehydrogenase|Succinate-semialdehyde dehydrogenase]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Synechococcus sp. pcc 7002]] | [[Category: Synechococcus sp. pcc 7002]] | ||
[[Category: Park, J | [[Category: Park, J]] | ||
[[Category: Rhee, S | [[Category: Rhee, S]] | ||
[[Category: Oxidoreductase]] | [[Category: Oxidoreductase]] | ||
[[Category: Rossmann fold]] | [[Category: Rossmann fold]] | ||
Revision as of 15:31, 21 December 2014
Structure of Bacterial EnzymeStructure of Bacterial Enzyme
Structural highlights
Publication Abstract from PubMedSuccinic semialdehyde dehydrogenase (SSADH) from cyanobacterium Synechococcus differs from other SSADHs in the gamma-aminobutyrate shunt. Synechococcus SSADH (SySSADH) is a TCA cycle enzyme and completes a 2-oxoglutarate dehydrogenase-deficient cyanobacterial TCA cycle through a detour metabolic pathway. SySSADH produces succinate in an NADP(+)-dependent manner with a single cysteine acting as the catalytic residue in the catalytic loop. Crystal structures of SySSADH were determined in their apo form, as a binary complex with NADP(+) and as a ternary complex with succinic semialdehyde and NADPH, providing details about the catalytic mechanism by revealing a covalent adduct of a cofactor with the catalytic cysteine in the binary complex and a proposed thiohemiacetal intermediate in the ternary complex. Further analyses showed that SySSADH is an oxidation-sensitive enzyme and that the formation of the NADP-cysteine adduct is a kinetically preferred event that protects the catalytic cysteine from H2O2-dependent oxidative stress. These structural and functional features of SySSADH provide a molecular basis for cofactor-dependent oxidation protection in 1-Cys SSADH, which is unique relative to other 2-Cys SSADHs employing a redox-dependent formation of a disulfide bridge. Structural Basis for a Cofactor-dependent Oxidation Protection and Catalysis of Cyanobacterial Succinic Semialdehyde Dehydrogenase.,Park J, Rhee S J Biol Chem. 2013 May 31;288(22):15760-70. doi: 10.1074/jbc.M113.460428. Epub, 2013 Apr 15. PMID:23589281[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
|
| ||||||||||||||||||