1ppy: Difference between revisions

Revision as of 05:21, 3 May 2008

Native precursor of pyruvoyl dependent Aspartate decarboxylase

OverviewOverview

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 StructureAbout this Structure

1PPY is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

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 05:21:04 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

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 [[Image:1ppy.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 1ppy |SIZE=350|CAPTION= <scene name='initialview01'>1ppy</scene>, resolution 1.95&Aring;
+The line below this paragraph, containing "STRUCTURE_1ppy", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=CSX:S-OXY+CYSTEINE'>CSX</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[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] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE= PAND OR B0131 OR C0160 OR Z0142 OR ECS0135 OR SF0128 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])
+-->
-|DOMAIN=
+{{STRUCTURE_1ppy|  PDB=1ppy  |  SCENE=  }}
-|RELATEDENTRY=[[1aw8|1aw8]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ppy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ppy OCA], [http://www.ebi.ac.uk/pdbsum/1ppy PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ppy RCSB]</span>
-}}
 '''Native precursor of pyruvoyl dependent Aspartate decarboxylase'''
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 [[Category: Webb, M E.]]
 [[Category: Witty, M.]]
-[[Category: decarboxylase]]
+[[Category: Decarboxylase]]
-[[Category: intramolecular protein self-processing]]
+[[Category: Intramolecular protein self-processing]]
-[[Category: pantothenate pathway]]
+[[Category: Pantothenate pathway]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 05:21:04 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:02:59 2008''