2v6a: Difference between revisions

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Revision as of 19:43, 20 March 2008

File:2v6a.jpg

, resolution 1.50Å

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Ligands:

, and

Activity:

Ribulose-bisphosphate carboxylase, with EC number 4.1.1.39

Coordinates:

save as pdb, mmCIF, xml

CRYSTAL STRUCTURE OF CHLAMYDOMONAS REINHARDTII RUBISCO WITH LARGE-SUBUNIT MUTATIONS V331A, G344S

OverviewOverview

The loop between alpha-helix 6 and beta-strand 6 in the alpha/beta-barrel of ribulose-1,5-bisphosphate carboxylase/oxygenase plays a key role in discriminating between CO2 and O2. Genetic screening in Chlamydomonas reinhardtii previously identified a loop-6 V331A substitution that decreases carboxylation and CO2/O2 specificity. Revertant selection identified T342I and G344S substitutions that restore photosynthetic growth by increasing carboxylation and specificity of the V331A enzyme. In numerous X-ray crystal structures, loop 6 is closed or open depending on the activation state of the enzyme and the presence or absence of ligands. The carboxy terminus folds over loop 6 in the closed state. To study the molecular basis for catalysis, directed mutagenesis and chloroplast transformation were used to create T342I and G344S substitutions alone. X-ray crystal structures were then solved for the V331A, V331A/T342I, T342I, and V331A/G344S enzymes, as well as for a D473E enzyme created to assess the role of the carboxy terminus in loop-6 closure. V331A disturbs a hydrophobic pocket, abolishing several van der Waals interactions. These changes are complemented by T342I and G344S, both of which alone cause decreases in CO2/O2 specificity. In the V331A/T342I revertant enzyme, Arg339 main-chain atoms are displaced. In V331A/G344S, alpha-helix 6 is shifted. D473E causes disorder of the carboxy terminus, but loop 6 remains closed. Interactions between a transition-state analogue and several residues are altered in the mutant enzymes. However, active-site Lys334 at the apex of loop 6 has a normal conformation. A variety of subtle interactions must be responsible for catalytic efficiency and CO2/O2 specificity.

About this StructureAbout this Structure

2V6A is a Protein complex structure of sequences from Chlamydomonas reinhardtii. Full crystallographic information is available from OCA.

ReferenceReference

Structural analysis of altered large-subunit loop-6/carboxy-terminus interactions that influence catalytic efficiency and CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase., Karkehabadi S, Satagopan S, Taylor TC, Spreitzer RJ, Andersson I, Biochemistry. 2007 Oct 2;46(39):11080-9. Epub 2007 Sep 8. PMID:17824672

Page seeded by OCA on Thu Mar 20 18:43:33 2008

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OCA

@@ Line 1: / Line 1: @@
-[[Image:2v6a.jpg|left|200px]]<br /><applet load="2v6a" size="350" color="white" frame="true" align="right" spinBox="true"
+[[Image:2v6a.jpg|left|200px]]
-caption="2v6a, resolution 1.50&Aring;" />
-'''CRYSTAL STRUCTURE OF CHLAMYDOMONAS REINHARDTII RUBISCO WITH LARGE-SUBUNIT MUTATIONS V331A, G344S'''<br />
+ {{Structure
+|PDB= 2v6a |SIZE=350|CAPTION= <scene name='initialview01'>2v6a</scene>, resolution 1.50&Aring;
+|SITE= <scene name='pdbsite=AC1:Edo+Binding+Site+For+Chain+L'>AC1</scene>
+|LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=CAP:2-CARBOXYARABINITOL-1,5-DIPHOSPHATE'>CAP</scene> and <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>
+|ACTIVITY= [http://en.wikipedia.org/wiki/Ribulose-bisphosphate_carboxylase Ribulose-bisphosphate carboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.39 4.1.1.39]
+|GENE=
+}}
+'''CRYSTAL STRUCTURE OF CHLAMYDOMONAS REINHARDTII RUBISCO WITH LARGE-SUBUNIT MUTATIONS V331A, G344S'''
 ==Overview==
@@ Line 7: / Line 16: @@
 ==About this Structure==
-V6A is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Chlamydomonas_reinhardtii Chlamydomonas reinhardtii] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=CAP:'>CAP</scene> and <scene name='pdbligand=EDO:'>EDO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribulose-bisphosphate_carboxylase Ribulose-bisphosphate carboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.39 4.1.1.39] Known structural/functional Site: <scene name='pdbsite=AC1:Edo+Binding+Site+For+Chain+L'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2V6A OCA].
+V6A is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Chlamydomonas_reinhardtii Chlamydomonas reinhardtii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2V6A OCA].
 ==Reference==
-Structural analysis of altered large-subunit loop-6/carboxy-terminus interactions that influence catalytic efficiency and CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase., Karkehabadi S, Satagopan S, Taylor TC, Spreitzer RJ, Andersson I, Biochemistry. 2007 Oct 2;46(39):11080-9. Epub 2007 Sep 8. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17824672 17824672]
+Structural analysis of altered large-subunit loop-6/carboxy-terminus interactions that influence catalytic efficiency and CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase., Karkehabadi S, Satagopan S, Taylor TC, Spreitzer RJ, Andersson I, Biochemistry. 2007 Oct 2;46(39):11080-9. Epub 2007 Sep 8. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17824672 17824672]
 [[Category: Chlamydomonas reinhardtii]]
 [[Category: Protein complex]]
@@ Line 41: / Line 50: @@
 [[Category: transit peptide]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:53:28 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 18:43:33 2008''