2pkq
From Proteopedia
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'''Crystal structure of the photosynthetic A2B2-glyceraldehyde-3-phosphate dehydrogenase, complexed with NADP''' | '''Crystal structure of the photosynthetic A2B2-glyceraldehyde-3-phosphate dehydrogenase, complexed with NADP''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | + | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PKQ OCA]. | |
==Reference== | ==Reference== | ||
Molecular mechanism of thioredoxin regulation in photosynthetic A2B2-glyceraldehyde-3-phosphate dehydrogenase., Fermani S, Sparla F, Falini G, Martelli PL, Casadio R, Pupillo P, Ripamonti A, Trost P, Proc Natl Acad Sci U S A. 2007 Jun 26;104(26):11109-14. Epub 2007 Jun 15. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17573533 17573533] | Molecular mechanism of thioredoxin regulation in photosynthetic A2B2-glyceraldehyde-3-phosphate dehydrogenase., Fermani S, Sparla F, Falini G, Martelli PL, Casadio R, Pupillo P, Ripamonti A, Trost P, Proc Natl Acad Sci U S A. 2007 Jun 26;104(26):11109-14. Epub 2007 Jun 15. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17573533 17573533] | ||
| - | [[Category: Glyceraldehyde-3-phosphate dehydrogenase (NADP(+)) (phosphorylating)]] | ||
| - | [[Category: Protein complex]] | ||
| - | [[Category: Spinacia oleracea]] | ||
[[Category: Falini, G.]] | [[Category: Falini, G.]] | ||
[[Category: Fermani, S.]] | [[Category: Fermani, S.]] | ||
[[Category: Ripamonti, A.]] | [[Category: Ripamonti, A.]] | ||
| - | [[Category: | + | [[Category: Oxidoreductase]] |
| - | [[Category: | + | [[Category: Protein-nadp complex]] |
| - | [[Category: | + | [[Category: Rossman fold]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 13:19:00 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 10:19, 4 May 2008
Crystal structure of the photosynthetic A2B2-glyceraldehyde-3-phosphate dehydrogenase, complexed with NADP
Overview
Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a light-regulated, NAD(P)H-dependent enzyme involved in plant photosynthetic carbon reduction. Unlike lower photosynthetic organisms, which only contain A(4)-GAPDH, the major GAPDH isoform of land plants is made up of A and B subunits, the latter containing a C-terminal extension (CTE) with fundamental regulatory functions. Light-activation of AB-GAPDH depends on the redox state of a pair of cysteines of the CTE, which can form a disulfide bond under control of thioredoxin f, leading to specific inhibition of the NADPH-dependent activity. The tridimensional structure of A(2)B(2)-GAPDH from spinach chloroplasts, crystallized in the oxidized state, shows that each disulfide-containing CTE is docked into a deep cleft between a pair of A and B subunits. The structure of the CTE was derived from crystallographic data and computational modeling and confirmed by site-specific mutagenesis. Structural analysis of oxidized A(2)B(2)-GAPDH and chimeric mutant [A+CTE](4)-GAPDH revealed that Arg-77, which is essential for coenzyme specificity and high NADPH-dependent activity, fails to interact with NADP in these kinetically inhibited GAPDH tetramers and is attracted instead by negative residues of oxidized CTE. Other subtle changes in catalytic domains and overall conformation of the tetramers were noticed in oxidized A(2)B(2)-GAPDH and [A+CTE](4)-GAPDH, compared with fully active A(4)-GAPDH. The CTE is envisioned as a redox-sensitive regulatory domain that can force AB-GAPDH into a kinetically inhibited conformation under oxidizing conditions, which also occur during dark inactivation of the enzyme in vivo.
About this Structure
Full crystallographic information is available from OCA.
Reference
Molecular mechanism of thioredoxin regulation in photosynthetic A2B2-glyceraldehyde-3-phosphate dehydrogenase., Fermani S, Sparla F, Falini G, Martelli PL, Casadio R, Pupillo P, Ripamonti A, Trost P, Proc Natl Acad Sci U S A. 2007 Jun 26;104(26):11109-14. Epub 2007 Jun 15. PMID:17573533 Page seeded by OCA on Sun May 4 13:19:00 2008
