View source for 1bnc

[[Image:1bnc.gif|left|200px]]

 {{Structure
|PDB= 1bnc |SIZE=350|CAPTION= <scene name='initialview01'>1bnc</scene>, resolution 2.4&Aring;
|SITE= 
|LIGAND= <scene name='pdbligand=PO4:PHOSPHATE ION'>PO4</scene>
|ACTIVITY= [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] 
|GENE= 
}}

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


==Overview==
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 Structure==
1BNC is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BNC OCA]. 

==Reference==
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:[http://www.ncbi.nlm.nih.gov/pubmed/7915138 7915138]
[[Category: Biotin carboxylase]]
[[Category: Escherichia coli]]
[[Category: Single protein]]
[[Category: Holden, H M.]]
[[Category: Rayment, I.]]
[[Category: Waldrop, G.]]
[[Category: PO4]]
[[Category: fatty acid biosynthesis]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 10:13:15 2008''