1pt1
From Proteopedia
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'''Unprocessed Pyruvoyl Dependent Aspartate Decarboxylase with Histidine 11 Mutated to Alanine''' | '''Unprocessed Pyruvoyl Dependent Aspartate Decarboxylase with Histidine 11 Mutated to Alanine''' | ||
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[[Category: Webb, M E.]] | [[Category: Webb, M E.]] | ||
[[Category: Witty, M.]] | [[Category: Witty, M.]] | ||
| - | [[Category: | + | [[Category: Decarboxylase]] |
| - | [[Category: | + | [[Category: Pantothenate pathway]] |
| - | [[Category: | + | [[Category: Protein self-processing]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 05:27:20 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 02:27, 3 May 2008
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. 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 Sat May 3 05:27:20 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. | Decarboxylase | Pantothenate pathway | Protein self-processing
