1pt1
From Proteopedia
(New page: 200px<br /><applet load="1pt1" size="450" color="white" frame="true" align="right" spinBox="true" caption="1pt1, resolution 1.90Å" /> '''Unprocessed Pyruvoyl...) |
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| - | [[Image:1pt1.jpg|left|200px]]<br /><applet load="1pt1" size=" | + | [[Image:1pt1.jpg|left|200px]]<br /><applet load="1pt1" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1pt1, resolution 1.90Å" /> | caption="1pt1, resolution 1.90Å" /> | ||
'''Unprocessed Pyruvoyl Dependent Aspartate Decarboxylase with Histidine 11 Mutated to Alanine'''<br /> | '''Unprocessed Pyruvoyl Dependent Aspartate Decarboxylase with Histidine 11 Mutated to Alanine'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Aspartate decarboxylase, which is translated as a pro-protein, undergoes | + | Aspartate decarboxylase, which is translated as a pro-protein, undergoes intramolecular self-cleavage at Gly24-Ser25. We have determined the crystal structures of an unprocessed native precursor, in addition to Ala24 insertion, Ala26 insertion and Gly24-->Ser, His11-->Ala, Ser25-->Ala, Ser25-->Cys and Ser25-->Thr mutants. Comparative analyses of the cleavage site reveal specific conformational constraints that govern self-processing and demonstrate that considerable rearrangement must occur. We suggest that Thr57 Ogamma and a water molecule form an 'oxyanion hole' that likely stabilizes the proposed oxyoxazolidine intermediate. Thr57 and this water molecule are probable catalytic residues able to support acid-base catalysis. The conformational freedom in the loop preceding the cleavage site appears to play a determining role in the reaction. The molecular mechanism of self-processing, presented here, emphasizes the importance of stabilization of the oxyoxazolidine intermediate. Comparison of the structural features shows significant similarity to those in other self-processing systems, and suggests that models of the cleavage site of such enzymes based on Ser-->Ala or Ser-->Thr mutants alone may lead to erroneous interpretations of the mechanism. |
==About this Structure== | ==About this Structure== | ||
| - | 1PT1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Aspartate_1-decarboxylase Aspartate 1-decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.11 4.1.1.11] Full crystallographic information is available from [http:// | + | 1PT1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Aspartate_1-decarboxylase Aspartate 1-decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.11 4.1.1.11] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PT1 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Abell, C.]] | [[Category: Abell, C.]] | ||
| - | [[Category: Blundell, T | + | [[Category: Blundell, T L.]] |
| - | [[Category: Chirgadze, D | + | [[Category: Chirgadze, D Y.]] |
| - | [[Category: Kilkenny, M | + | [[Category: Kilkenny, M L.]] |
| - | [[Category: Lobley, C | + | [[Category: Lobley, C M.C.]] |
[[Category: Matak-Vinkovic, D.]] | [[Category: Matak-Vinkovic, D.]] | ||
[[Category: Schmitzberger, F.]] | [[Category: Schmitzberger, F.]] | ||
| - | [[Category: Smith, A | + | [[Category: Smith, A G.]] |
[[Category: Vinkovic, M.]] | [[Category: Vinkovic, M.]] | ||
| - | [[Category: Webb, M | + | [[Category: Webb, M E.]] |
[[Category: Witty, M.]] | [[Category: Witty, M.]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
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[[Category: protein self-processing]] | [[Category: protein self-processing]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:32:14 2008'' |
Revision as of 12:32, 21 February 2008
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Unprocessed Pyruvoyl Dependent Aspartate Decarboxylase with Histidine 11 Mutated to Alanine
Overview
Aspartate decarboxylase, which is translated as a pro-protein, undergoes intramolecular self-cleavage at Gly24-Ser25. We have determined the crystal structures of an unprocessed native precursor, in addition to Ala24 insertion, Ala26 insertion and Gly24-->Ser, His11-->Ala, Ser25-->Ala, Ser25-->Cys and Ser25-->Thr mutants. Comparative analyses of the cleavage site reveal specific conformational constraints that govern self-processing and demonstrate that considerable rearrangement must occur. We suggest that Thr57 Ogamma and a water molecule form an 'oxyanion hole' that likely stabilizes the proposed oxyoxazolidine intermediate. Thr57 and this water molecule are probable catalytic residues able to support acid-base catalysis. The conformational freedom in the loop preceding the cleavage site appears to play a determining role in the reaction. The molecular mechanism of self-processing, presented here, emphasizes the importance of stabilization of the oxyoxazolidine intermediate. Comparison of the structural features shows significant similarity to those in other self-processing systems, and suggests that models of the cleavage site of such enzymes based on Ser-->Ala or Ser-->Thr mutants alone may lead to erroneous interpretations of the mechanism.
About this Structure
1PT1 is a Single protein structure of sequence from Escherichia coli with as ligand. Active as Aspartate 1-decarboxylase, with EC number 4.1.1.11 Full crystallographic information is available from OCA.
Reference
Structural constraints on protein self-processing in L-aspartate-alpha-decarboxylase., Schmitzberger F, Kilkenny ML, Lobley CM, Webb ME, Vinkovic M, Matak-Vinkovic D, Witty M, Chirgadze DY, Smith AG, Abell C, Blundell TL, EMBO J. 2003 Dec 1;22(23):6193-204. PMID:14633979
Page seeded by OCA on Thu Feb 21 14:32:14 2008
Categories: Aspartate 1-decarboxylase | Escherichia coli | Single protein | Abell, C. | Blundell, T L. | Chirgadze, D Y. | Kilkenny, M L. | Lobley, C M.C. | Matak-Vinkovic, D. | Schmitzberger, F. | Smith, A G. | Vinkovic, M. | Webb, M E. | Witty, M. | SO4 | Decarboxylase | Pantothenate pathway | Protein self-processing
