1lu0
From Proteopedia
(New page: 200px<br /><applet load="1lu0" size="450" color="white" frame="true" align="right" spinBox="true" caption="1lu0, resolution 1.03Å" /> '''Atomic Resolution St...) |
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| - | [[Image:1lu0.jpg|left|200px]]<br /><applet load="1lu0" size=" | + | [[Image:1lu0.jpg|left|200px]]<br /><applet load="1lu0" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1lu0, resolution 1.03Å" /> | caption="1lu0, resolution 1.03Å" /> | ||
'''Atomic Resolution Structure of Squash Trypsin Inhibitor: Unexpected Metal Coordination'''<br /> | '''Atomic Resolution Structure of Squash Trypsin Inhibitor: Unexpected Metal Coordination'''<br /> | ||
==Overview== | ==Overview== | ||
| - | CMTI-I, a small-protein trypsin inhibitor, has been crystallized as a 4:1 | + | CMTI-I, a small-protein trypsin inhibitor, has been crystallized as a 4:1 protein-zinc complex. The metal is coordinated in a symmetric tetrahedral fashion by glutamate/glutamic acid side chains. The structure was solved by direct methods in the absence of prior knowledge of the special position metal centre and refined with anisotropic displacement parameters using diffraction data extending to 1.03 A. In the final calculations, the main-chain atoms of low B(eq) values were refined without restraint control. The two molecules in the asymmetric unit have a conformation that is very similar to that reported earlier for CMTI-I in complex with trypsin, despite the Met8Leu mutation of the present variant. The only significant differences are in the enzyme-binding epitope (including the Arg5 residue) and in a higher mobility loop around Glu24. The present crystal structure contains organic solvent molecules (glycerol, MPD) that interact with the inhibitor molecules in an area that is at the enzyme-inhibitor interface in the CMTI-I-trypsin complex. A perfectly ordered residue (Ala18) has an unusual Ramachandran conformation as a result of geometrical strain introduced by the three disulfide bridges that clamp the protein fold. The results confirm deficiencies of some stereochemical restraints, such as peptide planarity or the N-C(alpha)-C angle, and suggest a link between their violations and hydrogen bonding. |
==About this Structure== | ==About this Structure== | ||
| - | 1LU0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cucurbita_maxima Cucurbita maxima] with ZN, SO4, MRD and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1LU0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cucurbita_maxima Cucurbita maxima] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=MRD:'>MRD</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LU0 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bierzynski, A.]] | [[Category: Bierzynski, A.]] | ||
[[Category: Jaskolski, M.]] | [[Category: Jaskolski, M.]] | ||
| - | [[Category: Sheldrick, G | + | [[Category: Sheldrick, G M.]] |
[[Category: Thaimattam, R.]] | [[Category: Thaimattam, R.]] | ||
[[Category: Tykarska, E.]] | [[Category: Tykarska, E.]] | ||
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[[Category: serine protease inhibitor]] | [[Category: serine protease inhibitor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:48:26 2008'' |
Revision as of 11:48, 21 February 2008
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Atomic Resolution Structure of Squash Trypsin Inhibitor: Unexpected Metal Coordination
Overview
CMTI-I, a small-protein trypsin inhibitor, has been crystallized as a 4:1 protein-zinc complex. The metal is coordinated in a symmetric tetrahedral fashion by glutamate/glutamic acid side chains. The structure was solved by direct methods in the absence of prior knowledge of the special position metal centre and refined with anisotropic displacement parameters using diffraction data extending to 1.03 A. In the final calculations, the main-chain atoms of low B(eq) values were refined without restraint control. The two molecules in the asymmetric unit have a conformation that is very similar to that reported earlier for CMTI-I in complex with trypsin, despite the Met8Leu mutation of the present variant. The only significant differences are in the enzyme-binding epitope (including the Arg5 residue) and in a higher mobility loop around Glu24. The present crystal structure contains organic solvent molecules (glycerol, MPD) that interact with the inhibitor molecules in an area that is at the enzyme-inhibitor interface in the CMTI-I-trypsin complex. A perfectly ordered residue (Ala18) has an unusual Ramachandran conformation as a result of geometrical strain introduced by the three disulfide bridges that clamp the protein fold. The results confirm deficiencies of some stereochemical restraints, such as peptide planarity or the N-C(alpha)-C angle, and suggest a link between their violations and hydrogen bonding.
About this Structure
1LU0 is a Single protein structure of sequence from Cucurbita maxima with , , and as ligands. Full crystallographic information is available from OCA.
Reference
Atomic resolution structure of squash trypsin inhibitor: unexpected metal coordination., Thaimattam R, Tykarska E, Bierzynski A, Sheldrick GM, Jaskolski M, Acta Crystallogr D Biol Crystallogr. 2002 Sep;58(Pt 9):1448-61. Epub 2002, Aug 23. PMID:12198301
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