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1bnc
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(New page: 200px<br /><applet load="1bnc" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bnc, resolution 2.4Å" /> '''THREE-DIMENSIONAL STR...) |
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| - | [[Image:1bnc.gif|left|200px]]<br /><applet load="1bnc" size=" | + | [[Image:1bnc.gif|left|200px]]<br /><applet load="1bnc" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1bnc, resolution 2.4Å" /> | caption="1bnc, resolution 2.4Å" /> | ||
'''THREE-DIMENSIONAL STRUCTURE OF THE BIOTIN CARBOXYLASE SUBUNIT OF ACETYL-COA CARBOXYLASE'''<br /> | '''THREE-DIMENSIONAL STRUCTURE OF THE BIOTIN CARBOXYLASE SUBUNIT OF ACETYL-COA CARBOXYLASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Acetyl-CoA carboxylase is found in all animals, plants, and bacteria and | + | 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== | ==About this Structure== | ||
| - | 1BNC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with PO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [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] Full crystallographic information is available from [http:// | + | 1BNC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=PO4:'>PO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BNC OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Holden, H | + | [[Category: Holden, H M.]] |
[[Category: Rayment, I.]] | [[Category: Rayment, I.]] | ||
[[Category: Waldrop, G.]] | [[Category: Waldrop, G.]] | ||
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[[Category: fatty acid biosynthesis]] | [[Category: fatty acid biosynthesis]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:57:03 2008'' |
Revision as of 09:57, 21 February 2008
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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 Escherichia coli with as ligand. Active as Biotin carboxylase, with EC number 6.3.4.14 Full crystallographic information is available from 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:7915138
Page seeded by OCA on Thu Feb 21 11:57:03 2008
