2b4k: Difference between revisions

Revision as of 19:50, 3 May 2008

Acetobacter turbidans alpha-amino acid ester hydrolase complexed with phenylglycine

OverviewOverview

The alpha-amino acid ester hydrolase (AEH) from Acetobacter turbidans is a bacterial enzyme catalyzing the hydrolysis and synthesis of beta-lactam antibiotics. The crystal structures of the native enzyme, both unliganded and in complex with the hydrolysis product D-phenylglycine are reported, as well as the structures of an inactive mutant (S205A) complexed with the substrate ampicillin, and an active site mutant (Y206A) with an increased tendency to catalyze antibiotic production rather than hydrolysis. The structure of the native enzyme shows an acyl binding pocket, in which D-phenylglycine binds, and an additional space that is large enough to accommodate the beta-lactam moiety of an antibiotic. In the S205A mutant, ampicillin binds in this pocket in a non-productive manner, making extensive contacts with the side chain of Tyr(112), which also participates in oxyanion hole formation. In the Y206A mutant, the Tyr(112) side chain has moved with its hydroxyl group toward the catalytic serine. Because this changes the properties of the beta-lactam binding site, this could explain the increased beta-lactam transferase activity of this mutant.

About this StructureAbout this Structure

2B4K is a Single protein structure of sequence from Acetobacter pasteurianus. Full crystallographic information is available from OCA.

ReferenceReference

Acetobacter turbidans alpha-amino acid ester hydrolase: how a single mutation improves an antibiotic-producing enzyme., Barends TR, Polderman-Tijmes JJ, Jekel PA, Williams C, Wybenga G, Janssen DB, Dijkstra BW, J Biol Chem. 2006 Mar 3;281(9):5804-10. Epub 2005 Dec 23. PMID:16377627 Page seeded by OCA on Sat May 3 19:50:53 2008

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

OCA

@@ Line 1: / Line 1: @@
 [[Image:2b4k.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 2b4k |SIZE=350|CAPTION= <scene name='initialview01'>2b4k</scene>, resolution 3.30&Aring;
+The line below this paragraph, containing "STRUCTURE_2b4k", 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=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=PG9:D-PHENYLGLYCINE'>PG9</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/Alpha-amino-acid_esterase Alpha-amino-acid esterase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.43 3.1.1.43] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE= aehA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=438 Acetobacter pasteurianus])
+-->
-|DOMAIN=
+{{STRUCTURE_2b4k|  PDB=2b4k  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2b4k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2b4k OCA], [http://www.ebi.ac.uk/pdbsum/2b4k PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2b4k RCSB]</span>
-}}
 '''Acetobacter turbidans alpha-amino acid ester hydrolase complexed with phenylglycine'''
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 [[Category: Williams, C.]]
 [[Category: Wybenga, G.]]
-[[Category: alpha-beta hydrolase]]
+[[Category: Alpha-beta hydrolase]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 19:50:53 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 02:01:23 2008''