1g0m
From Proteopedia
(New page: 200px<br /><applet load="1g0m" size="450" color="white" frame="true" align="right" spinBox="true" caption="1g0m, resolution 1.7Å" /> '''CRYSTAL STRUCTURE OF ...) |
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| - | [[Image:1g0m.jpg|left|200px]]<br /><applet load="1g0m" size=" | + | [[Image:1g0m.jpg|left|200px]]<br /><applet load="1g0m" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1g0m, resolution 1.7Å" /> | caption="1g0m, resolution 1.7Å" /> | ||
'''CRYSTAL STRUCTURE OF T4 LYSOZYME MUTANT T152I'''<br /> | '''CRYSTAL STRUCTURE OF T4 LYSOZYME MUTANT T152I'''<br /> | ||
==Overview== | ==Overview== | ||
| - | To investigate the structural and thermodynamic basis of the binding of | + | To investigate the structural and thermodynamic basis of the binding of solvent at internal sites within proteins a number of mutations were constructed in T4 lysozyme. Some of these were designed to introduce new solvent-binding sites. Others were intended to displace solvent from preexisting sites. In one case Val-149 was replaced with alanine, serine, cysteine, threonine, isoleucine, and glycine. Crystallographic analysis shows that, with the exception of isoleucine, each of these substitutions results in the binding of solvent at a polar site that is sterically blocked in the wild-type enzyme. Mutations designed to perturb or displace a solvent molecule present in the native enzyme included the replacement of Thr-152 with alanine, serine, cysteine, valine, and isoleucine. Although the solvent molecule was moved in some cases by up to 1.7 A, in no case was it completely removed from the folded protein. The results suggest that hydrogen bonds from the protein to bound solvent are energy neutral. The binding of solvent to internal sites within proteins also appears to be energy neutral except insofar as the bound solvent may prevent a loss of energy due to potential hydrogen bonding groups that would otherwise be unsatisfied. The introduction of a solvent-binding site appears to require not only a cavity to accommodate the water molecule but also the presence of polar groups to help satisfy its hydrogen-bonding potential. It may be easier to design a site to accommodate two or more water molecules rather than one as the solvent molecules can then hydrogen-bond to each other. For similar reasons it is often difficult to design a point mutation that will displace a single solvent molecule from the core of a protein. |
==About this Structure== | ==About this Structure== | ||
| - | 1G0M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4] with CL and HED as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] Full crystallographic information is available from [http:// | + | 1G0M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4] with <scene name='pdbligand=CL:'>CL</scene> and <scene name='pdbligand=HED:'>HED</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G0M OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Lysozyme]] | [[Category: Lysozyme]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Baase, W | + | [[Category: Baase, W A.]] |
| - | [[Category: Matthews, B | + | [[Category: Matthews, B W.]] |
| - | [[Category: Quillin, M | + | [[Category: Quillin, M L.]] |
[[Category: Xu, J.]] | [[Category: Xu, J.]] | ||
[[Category: CL]] | [[Category: CL]] | ||
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[[Category: o-glycosyl]] | [[Category: o-glycosyl]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:44:45 2008'' |
Revision as of 10:44, 21 February 2008
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CRYSTAL STRUCTURE OF T4 LYSOZYME MUTANT T152I
Overview
To investigate the structural and thermodynamic basis of the binding of solvent at internal sites within proteins a number of mutations were constructed in T4 lysozyme. Some of these were designed to introduce new solvent-binding sites. Others were intended to displace solvent from preexisting sites. In one case Val-149 was replaced with alanine, serine, cysteine, threonine, isoleucine, and glycine. Crystallographic analysis shows that, with the exception of isoleucine, each of these substitutions results in the binding of solvent at a polar site that is sterically blocked in the wild-type enzyme. Mutations designed to perturb or displace a solvent molecule present in the native enzyme included the replacement of Thr-152 with alanine, serine, cysteine, valine, and isoleucine. Although the solvent molecule was moved in some cases by up to 1.7 A, in no case was it completely removed from the folded protein. The results suggest that hydrogen bonds from the protein to bound solvent are energy neutral. The binding of solvent to internal sites within proteins also appears to be energy neutral except insofar as the bound solvent may prevent a loss of energy due to potential hydrogen bonding groups that would otherwise be unsatisfied. The introduction of a solvent-binding site appears to require not only a cavity to accommodate the water molecule but also the presence of polar groups to help satisfy its hydrogen-bonding potential. It may be easier to design a site to accommodate two or more water molecules rather than one as the solvent molecules can then hydrogen-bond to each other. For similar reasons it is often difficult to design a point mutation that will displace a single solvent molecule from the core of a protein.
About this Structure
1G0M is a Single protein structure of sequence from Bacteriophage t4 with and as ligands. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
Reference
Structural and thermodynamic analysis of the binding of solvent at internal sites in T4 lysozyme., Xu J, Baase WA, Quillin ML, Baldwin EP, Matthews BW, Protein Sci. 2001 May;10(5):1067-78. PMID:11316887
Page seeded by OCA on Thu Feb 21 12:44:45 2008
Categories: Bacteriophage t4 | Lysozyme | Single protein | Baase, W A. | Matthews, B W. | Quillin, M L. | Xu, J. | CL | HED | Bacteriolytic enzyme | Glycosidase | Hydrolase | O-glycosyl
