1bnc: Difference between revisions

Revision as of 11:43, 2 May 2008

THREE-DIMENSIONAL STRUCTURE OF THE BIOTIN CARBOXYLASE SUBUNIT OF ACETYL-COA CARBOXYLASE

OverviewOverview

Acetyl-CoA carboxylase is found in all animals, plants, and bacteria and catalyzes the first committed step in fatty acid synthesis. It is a multicomponent enzyme containing a biotin carboxylase activity, a biotin carboxyl carrier protein, and a carboxyltransferase functionality. Here we report the X-ray structure of the biotin carboxylase component from Escherichia coli determined to 2.4-A resolution. The structure was solved by a combination of multiple isomorphous replacement and electron density modification procedures. The overall fold of the molecule may be described in terms of three structural domains. The N-terminal region, formed by Met 1-Ile 103, adopts a dinucleotide binding motif with five strands of parallel beta-sheet flanked on either side by alpha-helices. The "B-domain" extends from the main body of the subunit where it folds into two alpha-helical regions and three strands of beta-sheet. Following the excursion into the B-domain, the polypeptide chain folds back into the body of the protein where it forms an eight-stranded antiparallel beta-sheet. In addition to this major secondary structural element, the C-terminal domain also contains a smaller three-stranded antiparallel beta-sheet and seven alpha-helices. The active site of the enzyme has been identified tentatively by a difference Fourier map calculated between X-ray data from the native crystals and from crystals soaked in a Ag+/biotin complex. Those amino acid residues believed to form part of the active site pocket include His 209-Glu 211, His 236-Glu 241, Glu 276, Ile 287-Glu 296, and Arg 338.2+ represents the first X-ray model of a biotin-dependent carboxylase.

About this StructureAbout this Structure

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

ReferenceReference

Three-dimensional structure of the biotin carboxylase subunit of acetyl-CoA carboxylase., Waldrop GL, Rayment I, Holden HM, Biochemistry. 1994 Aug 30;33(34):10249-56. PMID:7915138 Page seeded by OCA on Fri May 2 11:43:56 2008

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

OCA

@@ Line 1: / Line 1: @@
 [[Image:1bnc.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 1bnc |SIZE=350|CAPTION= <scene name='initialview01'>1bnc</scene>, resolution 2.4&Aring;
+The line below this paragraph, containing "STRUCTURE_1bnc", 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=PO4:PHOSPHATE+ION'>PO4</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/Biotin_carboxylase Biotin carboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.4.14 6.3.4.14] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1bnc|  PDB=1bnc  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1bnc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bnc OCA], [http://www.ebi.ac.uk/pdbsum/1bnc PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1bnc RCSB]</span>
-}}
 '''THREE-DIMENSIONAL STRUCTURE OF THE BIOTIN CARBOXYLASE SUBUNIT OF ACETYL-COA CARBOXYLASE'''
@@ Line 29: / Line 26: @@
 [[Category: Rayment, I.]]
 [[Category: Waldrop, G.]]
-[[Category: fatty acid biosynthesis]]
+[[Category: Fatty acid biosynthesis]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 11:43:56 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:04:22 2008''