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Crystal structure of activated ribulose-1,5-bisphosphate carboxylase/oxygenase from green alga Chlamydomonas reinhardtii complexed with 2-carboxyarabinitol-1,5-bisphosphate
- Source :
- Journal of Molecular Biology. 316:679-691
- Publication Year :
- 2002
- Publisher :
- Elsevier BV, 2002.
-
Abstract
- Ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) catalyzes the initial steps of photosynthetic carbon reduction and photorespiratory carbon oxidation cycles by combining CO(2) and O(2), respectively, with ribulose-1,5-bisphosphate. Many photosynthetic organisms have form I rubiscos comprised of eight large (L) and eight small (S) subunits. The crystal structure of the complex of activated rubisco from the green alga Chlamydomonas reinhardtii and the reaction intermediate analogue 2-carboxyarabinitol-1,5-bisphosphate (2-CABP) has been solved at 1.84 A resolution (R(cryst) of 15.2 % and R(free) of 18.1 %). The subunit arrangement of Chlamydomonas rubisco is the same as those of the previously solved form I rubiscos. Especially, the present structure is very similar to the activated spinach structure complexed with 2-CABP in the L-subunit folding and active-site conformation, but differs in S-subunit folding. The central insertion of the Chlamydomonas S-subunit forms the longer betaA-betaB loop that protrudes deeper into the solvent channel of rubisco than higher plant, cyanobacterial, and red algal (red-like) betaA-betaB loops. The C-terminal extension of the Chlamydomonas S-subunit does not protrude into the solvent channel, unlike that of the red algal S-subunit, but lies on the protein surface anchored by interactions with the N-terminal region of the S-subunit. Further, the present high-resolution structure has revealed novel post-translational modifications. Residue 1 of the S-subunit is N(alpha)-methylmethionine, residues 104 and 151 of the L-subunit are 4-hydroxyproline, and residues 256 and 369 of the L-subunit are S(gamma)-methylcysteine. Furthermore, the unusual electron density of residue 471 of the L-subunit, which has been deduced to be threonine from the genomic DNA sequence, suggests that the residue is isoleucine produced by RNA editing or O(gamma)-methylthreonine.
- Subjects :
- Models, Molecular
Protein Folding
Stereochemistry
Ribulose-Bisphosphate Carboxylase
Molecular Sequence Data
Chlamydomonas reinhardtii
Crystallography, X-Ray
Photosynthesis
Methylation
Protein Structure, Secondary
chemistry.chemical_compound
Sugar Alcohols
Protein structure
Spinacia oleracea
Structural Biology
Animals
Amino Acid Sequence
Protein Structure, Quaternary
Molecular Biology
Pentosephosphates
Binding Sites
Ribulose 1,5-bisphosphate
biology
Chlamydomonas
RuBisCO
food and beverages
Lyase
biology.organism_classification
Enzyme Activation
Kinetics
Protein Subunits
chemistry
Biochemistry
biology.protein
Protein folding
RNA Editing
Protein Processing, Post-Translational
Sequence Alignment
Subjects
Details
- ISSN :
- 00222836
- Volume :
- 316
- Database :
- OpenAIRE
- Journal :
- Journal of Molecular Biology
- Accession number :
- edsair.doi.dedup.....fbe7ef93b5c193a305720e773c012fa9