1n3z
From Proteopedia
(New page: 200px<br /><applet load="1n3z" size="450" color="white" frame="true" align="right" spinBox="true" caption="1n3z, resolution 1.65Å" /> '''Crystal structure of...) |
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| - | [[Image:1n3z.gif|left|200px]]<br /><applet load="1n3z" size=" | + | [[Image:1n3z.gif|left|200px]]<br /><applet load="1n3z" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1n3z, resolution 1.65Å" /> | caption="1n3z, resolution 1.65Å" /> | ||
'''Crystal structure of the [S-carboxyamidomethyl-Cys31, S-carboxyamidomethyl-Cys32] monomeric derivative of the bovine seminal ribonuclease in the liganded state'''<br /> | '''Crystal structure of the [S-carboxyamidomethyl-Cys31, S-carboxyamidomethyl-Cys32] monomeric derivative of the bovine seminal ribonuclease in the liganded state'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Bovine seminal ribonuclease, a homodimeric enzyme joined covalently by two | + | Bovine seminal ribonuclease, a homodimeric enzyme joined covalently by two interchain disulphide bonds, is an equilibrium mixture of two conformational isomers, MxM and M=M. The major form, MxM, whose crystal structure has been previously determined at 1.9 A resolution, presents the swapping of the N-terminal segments (residues 1-15) and composite active sites formed by residues of different chains. The three-dimensional domain swapping does not occur in the M=M form. The different fold of each N-terminal tail is directed by the hinge loop (residue 16-22) connecting the swapping domain to the body of the protein. Reduction and alkylation of interchain disulphide bridges produce a monomeric derivative and a noncovalent swapped dimer, which are both active. The free and nucleotide-bound forms of the monomer have been crystallized at an alkaline pH and refined at 1.45 and 1.65 A resolution, respectively. In both cases, the N-terminal fragment is folded on the main body of the protein to produce an intact active site and a chain architecture very similar to that of bovine pancreatic ribonuclease. In this new fold of the seminal chain, the hinge loop is disordered. Despite the difference between the tertiary structure of the monomer and that of the chains in the MxM form, the active sites of the two enzymes are virtually indistinguishable. Furthermore, the structure of the liganded enzyme represents the first example of a ribonuclease complex studied at an alkaline pH and provides new information on the binding of a nucleotide when the catalytic histidines are deprotonated. |
==About this Structure== | ==About this Structure== | ||
| - | 1N3Z is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with U3P and ADN as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Pancreatic_ribonuclease Pancreatic ribonuclease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.27.5 3.1.27.5] Full crystallographic information is available from [http:// | + | 1N3Z is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=U3P:'>U3P</scene> and <scene name='pdbligand=ADN:'>ADN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Pancreatic_ribonuclease Pancreatic ribonuclease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.27.5 3.1.27.5] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N3Z OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Pancreatic ribonuclease]] | [[Category: Pancreatic ribonuclease]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Fiore, A | + | [[Category: Fiore, A Di.]] |
[[Category: Mazzarella, L.]] | [[Category: Mazzarella, L.]] | ||
[[Category: Sica, F.]] | [[Category: Sica, F.]] | ||
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[[Category: protein-nucleotide complex]] | [[Category: protein-nucleotide complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:01:58 2008'' |
Revision as of 12:02, 21 February 2008
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Crystal structure of the [S-carboxyamidomethyl-Cys31, S-carboxyamidomethyl-Cys32] monomeric derivative of the bovine seminal ribonuclease in the liganded state
Overview
Bovine seminal ribonuclease, a homodimeric enzyme joined covalently by two interchain disulphide bonds, is an equilibrium mixture of two conformational isomers, MxM and M=M. The major form, MxM, whose crystal structure has been previously determined at 1.9 A resolution, presents the swapping of the N-terminal segments (residues 1-15) and composite active sites formed by residues of different chains. The three-dimensional domain swapping does not occur in the M=M form. The different fold of each N-terminal tail is directed by the hinge loop (residue 16-22) connecting the swapping domain to the body of the protein. Reduction and alkylation of interchain disulphide bridges produce a monomeric derivative and a noncovalent swapped dimer, which are both active. The free and nucleotide-bound forms of the monomer have been crystallized at an alkaline pH and refined at 1.45 and 1.65 A resolution, respectively. In both cases, the N-terminal fragment is folded on the main body of the protein to produce an intact active site and a chain architecture very similar to that of bovine pancreatic ribonuclease. In this new fold of the seminal chain, the hinge loop is disordered. Despite the difference between the tertiary structure of the monomer and that of the chains in the MxM form, the active sites of the two enzymes are virtually indistinguishable. Furthermore, the structure of the liganded enzyme represents the first example of a ribonuclease complex studied at an alkaline pH and provides new information on the binding of a nucleotide when the catalytic histidines are deprotonated.
About this Structure
1N3Z is a Single protein structure of sequence from Bos taurus with and as ligands. Active as Pancreatic ribonuclease, with EC number 3.1.27.5 Full crystallographic information is available from OCA.
Reference
The unswapped chain of bovine seminal ribonuclease: Crystal structure of the free and liganded monomeric derivative., Sica F, Di Fiore A, Zagari A, Mazzarella L, Proteins. 2003 Aug 1;52(2):263-71. PMID:12833549
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