1m80
From Proteopedia
(New page: 200px<br /><applet load="1m80" size="450" color="white" frame="true" align="right" spinBox="true" caption="1m80, resolution 2.35Å" /> '''SUBSTRATE FREE FORM ...) |
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| - | [[Image:1m80.gif|left|200px]]<br /><applet load="1m80" size=" | + | [[Image:1m80.gif|left|200px]]<br /><applet load="1m80" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1m80, resolution 2.35Å" /> | caption="1m80, resolution 2.35Å" /> | ||
'''SUBSTRATE FREE FORM OF ARGININE KINASE'''<br /> | '''SUBSTRATE FREE FORM OF ARGININE KINASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Arginine kinase (AK) is a member of the guanidino kinase family that plays | + | Arginine kinase (AK) is a member of the guanidino kinase family that plays an important role in buffering ATP concentration in cells with high and fluctuating energy demands. The AK specifically catalyzes the reversible phosphoryl transfer between ATP and arginine. We have determined the crystal structure of AK from the horseshoe crab (Limulus polyphemus) in its open (substrate-free) form. The final model has been refined at 2.35 A with a final R of 22.3% (R(free) = 23.7%). The structure of the open form is compared to the previously determined structure of the transition state analog complex in the closed form. Classically, the protein would be considered two domain, but dynamic domain (DynDom) analysis shows that most of the differences between the two structures can be considered as the motion between four rigid groups of nonsequential residues. ATP binds near a cluster of positively charged residues of a fixed dynamic domain. The other three dynamic domains close the active site with separate hinge rotations relative to the fixed domain. Several residues of key importance for the induced motion are conserved within the phosphagen kinase family, including creatine kinase. Substantial conformational changes are induced in different parts of the enzyme as intimate interactions are formed with both substrates. Thus, although induced fit occurs in a number of phosphoryl transfer enzymes, the conformational changes in phosphagen kinases appear to be more complicated than in prior examples. |
==About this Structure== | ==About this Structure== | ||
| - | 1M80 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Limulus_polyphemus Limulus polyphemus]. Active as [http://en.wikipedia.org/wiki/Arginine_kinase Arginine kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.3.3 2.7.3.3] Full crystallographic information is available from [http:// | + | 1M80 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Limulus_polyphemus Limulus polyphemus]. Active as [http://en.wikipedia.org/wiki/Arginine_kinase Arginine kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.3.3 2.7.3.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M80 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Limulus polyphemus]] | [[Category: Limulus polyphemus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chapman, M | + | [[Category: Chapman, M S.]] |
| - | [[Category: Clark, S | + | [[Category: Clark, S A.]] |
| - | [[Category: Ellington, W | + | [[Category: Ellington, W R.]] |
| - | [[Category: Pruett, P | + | [[Category: Pruett, P K.]] |
[[Category: Somasundaram, T.]] | [[Category: Somasundaram, T.]] | ||
| - | [[Category: Yousef, M | + | [[Category: Yousef, M S.]] |
[[Category: arginine kinase]] | [[Category: arginine kinase]] | ||
[[Category: creatine kinase]] | [[Category: creatine kinase]] | ||
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[[Category: induced fit]] | [[Category: induced fit]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:52:29 2008'' |
Revision as of 11:52, 21 February 2008
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SUBSTRATE FREE FORM OF ARGININE KINASE
Overview
Arginine kinase (AK) is a member of the guanidino kinase family that plays an important role in buffering ATP concentration in cells with high and fluctuating energy demands. The AK specifically catalyzes the reversible phosphoryl transfer between ATP and arginine. We have determined the crystal structure of AK from the horseshoe crab (Limulus polyphemus) in its open (substrate-free) form. The final model has been refined at 2.35 A with a final R of 22.3% (R(free) = 23.7%). The structure of the open form is compared to the previously determined structure of the transition state analog complex in the closed form. Classically, the protein would be considered two domain, but dynamic domain (DynDom) analysis shows that most of the differences between the two structures can be considered as the motion between four rigid groups of nonsequential residues. ATP binds near a cluster of positively charged residues of a fixed dynamic domain. The other three dynamic domains close the active site with separate hinge rotations relative to the fixed domain. Several residues of key importance for the induced motion are conserved within the phosphagen kinase family, including creatine kinase. Substantial conformational changes are induced in different parts of the enzyme as intimate interactions are formed with both substrates. Thus, although induced fit occurs in a number of phosphoryl transfer enzymes, the conformational changes in phosphagen kinases appear to be more complicated than in prior examples.
About this Structure
1M80 is a Single protein structure of sequence from Limulus polyphemus. Active as Arginine kinase, with EC number 2.7.3.3 Full crystallographic information is available from OCA.
Reference
Induced fit in guanidino kinases--comparison of substrate-free and transition state analog structures of arginine kinase., Yousef MS, Clark SA, Pruett PK, Somasundaram T, Ellington WR, Chapman MS, Protein Sci. 2003 Jan;12(1):103-11. PMID:12493833
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