8ruc: Difference between revisions
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==Overview== | ==Overview== | ||
Ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from spinach is, a hexadecamer (L8S8, Mr = 550,000) consisting of eight large (L, 475, residues) and eight small subunits (S, 123 residues). High-resolution data, collection on crystals with large unit cells is not a trivial task due to, the effect of radiation damage and the large number of overlapping, reflections when conventional data collection methods are used. In order, to minimise these effects, data on rubisco were collected with a giant, Weissenberg camera at long crystal to image-plate distances at the, synchrotron of the Photon Factory, Japan. Relative to conventional data, sets, this experimental arrangement allowed a 20 to 30-fold reduction of, the X-ray dose/exposure time for data collection. This paper describes ... | Ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from spinach is, a hexadecamer (L8S8, Mr = 550,000) consisting of eight large (L, 475, residues) and eight small subunits (S, 123 residues). High-resolution data, collection on crystals with large unit cells is not a trivial task due to, the effect of radiation damage and the large number of overlapping, reflections when conventional data collection methods are used. In order, to minimise these effects, data on rubisco were collected with a giant, Weissenberg camera at long crystal to image-plate distances at the, synchrotron of the Photon Factory, Japan. Relative to conventional data, sets, this experimental arrangement allowed a 20 to 30-fold reduction of, the X-ray dose/exposure time for data collection. This paper describes the, refined 1.6 A crystal structure of activated rubisco complexed with a, transition state analogue, 2-carboxyarabinitol-bisphosphate. The, crystallographic asymmetric unit contains an L4S4 unit, representing half, of the molecule. The structure presented here is currently the highest, resolution structure for any protein of comparable size. Refinement of the, model was carried out by restrained least squares techniques without, non-crystallographic symmetry averaging. The results show that all L and S, subunits have identical three-dimensional structures, and their, arrangement within the hexadecamer has no intrinsic asymmetry. A detailed, analysis of the high-resolution maps identified 30 differences in the, sequence of the small subunit, indicating a larger than usual, heterogeneity for this nuclear encoded protein in spinach. No such, differences were found in the sequence of the chloroplast encoded large, subunit. The transition state analogue is in the cis conformation at the, active site suggesting a key role for the carbamate of Lys201 in, catalysis. Analysis of the active site around the catalytically essential, magnesium ion further indicates that residues in the second liganding, sphere of the metal play a role in fine-tuning the acid-base character and, the position of the residues directly liganded to the metal. | ||
==About this Structure== | ==About this Structure== | ||
8RUC is a | 8RUC is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Spinacia_oleracea Spinacia oleracea] with MG and CAP as [http://en.wikipedia.org/wiki/ligands ligands]. This structure superseeds the now removed PDB entry 8RUB. The following page contains interesting information on the relation of 8RUC with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb11_1.html Rubisco]]. 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] Structure known Active Sites: ACA, ACC, ACE and ACG. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=8RUC OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: photosynthesis]] | [[Category: photosynthesis]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:54:59 2007'' | ||
Revision as of 15:49, 5 November 2007
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ACTIVATED SPINACH RUBISCO COMPLEXED WITH 2-CARBOXYARABINITOL BISPHOSPHATE
OverviewOverview
Ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from spinach is, a hexadecamer (L8S8, Mr = 550,000) consisting of eight large (L, 475, residues) and eight small subunits (S, 123 residues). High-resolution data, collection on crystals with large unit cells is not a trivial task due to, the effect of radiation damage and the large number of overlapping, reflections when conventional data collection methods are used. In order, to minimise these effects, data on rubisco were collected with a giant, Weissenberg camera at long crystal to image-plate distances at the, synchrotron of the Photon Factory, Japan. Relative to conventional data, sets, this experimental arrangement allowed a 20 to 30-fold reduction of, the X-ray dose/exposure time for data collection. This paper describes the, refined 1.6 A crystal structure of activated rubisco complexed with a, transition state analogue, 2-carboxyarabinitol-bisphosphate. The, crystallographic asymmetric unit contains an L4S4 unit, representing half, of the molecule. The structure presented here is currently the highest, resolution structure for any protein of comparable size. Refinement of the, model was carried out by restrained least squares techniques without, non-crystallographic symmetry averaging. The results show that all L and S, subunits have identical three-dimensional structures, and their, arrangement within the hexadecamer has no intrinsic asymmetry. A detailed, analysis of the high-resolution maps identified 30 differences in the, sequence of the small subunit, indicating a larger than usual, heterogeneity for this nuclear encoded protein in spinach. No such, differences were found in the sequence of the chloroplast encoded large, subunit. The transition state analogue is in the cis conformation at the, active site suggesting a key role for the carbamate of Lys201 in, catalysis. Analysis of the active site around the catalytically essential, magnesium ion further indicates that residues in the second liganding, sphere of the metal play a role in fine-tuning the acid-base character and, the position of the residues directly liganded to the metal.
About this StructureAbout this Structure
8RUC is a Protein complex structure of sequences from Spinacia oleracea with MG and CAP as ligands. This structure superseeds the now removed PDB entry 8RUB. The following page contains interesting information on the relation of 8RUC with [Rubisco]. Active as Ribulose-bisphosphate carboxylase, with EC number 4.1.1.39 Structure known Active Sites: ACA, ACC, ACE and ACG. Full crystallographic information is available from OCA.
ReferenceReference
Large structures at high resolution: the 1.6 A crystal structure of spinach ribulose-1,5-bisphosphate carboxylase/oxygenase complexed with 2-carboxyarabinitol bisphosphate., Andersson I, J Mol Biol. 1996 May 31;259(1):160-74. PMID:8648644
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