2pek: Difference between revisions

Revision as of 19:28, 21 February 2008

Crystal structure of RbcX point mutant Q29A

OverviewOverview

After folding, many proteins must assemble into oligomeric complexes to become biologically active. Here we describe the role of RbcX as an assembly chaperone of ribulose-bisphosphate carboxylase/oxygenase (Rubisco), the enzyme responsible for the fixation of atmospheric carbon dioxide. In cyanobacteria and plants, Rubisco is an approximately 520 kDa complex composed of eight large subunits (RbcL) and eight small subunits (RbcS). We found that cyanobacterial RbcX functions downstream of chaperonin-mediated RbcL folding in promoting the formation of RbcL(8) core complexes. Structural analysis revealed that the 15 kDa RbcX forms a homodimer with two cooperating RbcL-binding regions. A central cleft specifically binds the exposed C-terminal peptide of RbcL subunits, enabling a peripheral surface of RbcX to mediate RbcL(8) assembly. Due to the dynamic nature of these interactions, RbcX is readily displaced from RbcL(8) complexes by RbcS, producing the active enzyme. The strategies employed by RbcX in achieving substrate specificity and efficient product release may be generally relevant in assisted assembly reactions.

About this StructureAbout this Structure

2PEK is a Single protein structure of sequence from Synechococcus elongatus pcc 7942. Full crystallographic information is available from OCA.

ReferenceReference

Structure and function of RbcX, an assembly chaperone for hexadecameric Rubisco., Saschenbrecker S, Bracher A, Rao KV, Rao BV, Hartl FU, Hayer-Hartl M, Cell. 2007 Jun 15;129(6):1189-200. PMID:17574029

Page seeded by OCA on Thu Feb 21 18:28:40 2008

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OCA

@@ Line 4: / Line 4: @@
 ==Overview==
-After folding, many proteins must assemble into oligomeric complexes to, become biologically active. Here we describe the role of RbcX as an, assembly chaperone of ribulose-bisphosphate carboxylase/oxygenase, (Rubisco), the enzyme responsible for the fixation of atmospheric carbon, dioxide. In cyanobacteria and plants, Rubisco is an approximately 520 kDa, complex composed of eight large subunits (RbcL) and eight small subunits, (RbcS). We found that cyanobacterial RbcX functions downstream of, chaperonin-mediated RbcL folding in promoting the formation of RbcL(8), core complexes. Structural analysis revealed that the 15 kDa RbcX forms a, homodimer with two cooperating RbcL-binding regions. A central cleft, specifically binds the exposed C-terminal peptide of RbcL subunits, enabling a peripheral surface of RbcX to mediate RbcL(8) assembly. Due to, the dynamic nature of these interactions, RbcX is readily displaced from, RbcL(8) complexes by RbcS, producing the active enzyme. The strategies, employed by RbcX in achieving substrate specificity and efficient product, release may be generally relevant in assisted assembly reactions.
+After folding, many proteins must assemble into oligomeric complexes to become biologically active. Here we describe the role of RbcX as an assembly chaperone of ribulose-bisphosphate carboxylase/oxygenase (Rubisco), the enzyme responsible for the fixation of atmospheric carbon dioxide. In cyanobacteria and plants, Rubisco is an approximately 520 kDa complex composed of eight large subunits (RbcL) and eight small subunits (RbcS). We found that cyanobacterial RbcX functions downstream of chaperonin-mediated RbcL folding in promoting the formation of RbcL(8) core complexes. Structural analysis revealed that the 15 kDa RbcX forms a homodimer with two cooperating RbcL-binding regions. A central cleft specifically binds the exposed C-terminal peptide of RbcL subunits, enabling a peripheral surface of RbcX to mediate RbcL(8) assembly. Due to the dynamic nature of these interactions, RbcX is readily displaced from RbcL(8) complexes by RbcS, producing the active enzyme. The strategies employed by RbcX in achieving substrate specificity and efficient product release may be generally relevant in assisted assembly reactions.
 ==About this Structure==
@@ Line 10: / Line 10: @@
 ==Reference==
-Structure and Function of RbcX, an Assembly Chaperone for Hexadecameric Rubisco., Saschenbrecker S, Bracher A, Rao KV, Rao BV, Hartl FU, Hayer-Hartl M, Cell. 2007 Jun 15;129(6):1189-200. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17574029 17574029]
+Structure and function of RbcX, an assembly chaperone for hexadecameric Rubisco., Saschenbrecker S, Bracher A, Rao KV, Rao BV, Hartl FU, Hayer-Hartl M, Cell. 2007 Jun 15;129(6):1189-200. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17574029 17574029]
 [[Category: Single protein]]
 [[Category: Synechococcus elongatus pcc 7942]]
 [[Category: Bracher, A.]]
-[[Category: Hartl, F.U.]]
+[[Category: Hartl, F U.]]
 [[Category: Hayer-Hartl, M.]]
-[[Category: Rao, B.Vasudeva.]]
+[[Category: Rao, B Vasudeva.]]
-[[Category: Rao, K.Vasudeva.]]
+[[Category: Rao, K Vasudeva.]]
 [[Category: Saschenbrecker, S.]]
 [[Category: chaperone]]
@@ Line 23: / Line 23: @@
 [[Category: protein complex assembly]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 14:36:04 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:28:40 2008''