4ake
From Proteopedia
(New page: 200px<br /><applet load="4ake" size="450" color="white" frame="true" align="right" spinBox="true" caption="4ake, resolution 2.2Å" /> '''ADENYLATE KINASE'''<b...) |
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| - | [[Image:4ake.gif|left|200px]]<br /><applet load="4ake" size=" | + | [[Image:4ake.gif|left|200px]]<br /><applet load="4ake" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="4ake, resolution 2.2Å" /> | caption="4ake, resolution 2.2Å" /> | ||
'''ADENYLATE KINASE'''<br /> | '''ADENYLATE KINASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: Adenylate kinases undergo large conformational changes during | + | BACKGROUND: Adenylate kinases undergo large conformational changes during their catalytic cycle. Because these changes have been studied by comparison of structures from different species, which share approximately one-third of their residues, only rough descriptions have been possible to date. RESULTS: We have solved the structure of unligated adenylate kinase from Escherichia coli at 2.2 degree resolution and compared it with the high-resolution structure of the same enzyme ligated with an inhibitor mimicking both substrates, ATP and AMP. This comparison shows that, upon substrate binding, the enzyme increases its chain mobility in a region remote from the active center. As this region 'solidifies' again on substrate release, we propose that it serves as a 'counterweight' balancing the substrate binding energy. CONCLUSION: The comparison of two very different conformations of the same polypeptide chain revealed kinematic details of the catalytic cycle. Moreover, it indicated that there exists an energetic counterweight compensating the substrate binding energy required for specificity. This counterweight prevents the enzyme from dropping into a rate-reducing energy well along the reaction coordinate. |
==About this Structure== | ==About this Structure== | ||
| - | 4AKE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Adenylate_kinase Adenylate kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.4.3 2.7.4.3] Full crystallographic information is available from [http:// | + | 4AKE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Adenylate_kinase Adenylate kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.4.3 2.7.4.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AKE OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Schlauderer, G | + | [[Category: Schlauderer, G J.]] |
| - | [[Category: Schulz, G | + | [[Category: Schulz, G E.]] |
[[Category: atp:amp phosphotransferase]] | [[Category: atp:amp phosphotransferase]] | ||
[[Category: myokinase]] | [[Category: myokinase]] | ||
[[Category: nucleoside monophosphate kinase]] | [[Category: nucleoside monophosphate kinase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:12:40 2008'' |
Revision as of 17:12, 21 February 2008
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ADENYLATE KINASE
Overview
BACKGROUND: Adenylate kinases undergo large conformational changes during their catalytic cycle. Because these changes have been studied by comparison of structures from different species, which share approximately one-third of their residues, only rough descriptions have been possible to date. RESULTS: We have solved the structure of unligated adenylate kinase from Escherichia coli at 2.2 degree resolution and compared it with the high-resolution structure of the same enzyme ligated with an inhibitor mimicking both substrates, ATP and AMP. This comparison shows that, upon substrate binding, the enzyme increases its chain mobility in a region remote from the active center. As this region 'solidifies' again on substrate release, we propose that it serves as a 'counterweight' balancing the substrate binding energy. CONCLUSION: The comparison of two very different conformations of the same polypeptide chain revealed kinematic details of the catalytic cycle. Moreover, it indicated that there exists an energetic counterweight compensating the substrate binding energy required for specificity. This counterweight prevents the enzyme from dropping into a rate-reducing energy well along the reaction coordinate.
About this Structure
4AKE is a Single protein structure of sequence from Escherichia coli. Active as Adenylate kinase, with EC number 2.7.4.3 Full crystallographic information is available from OCA.
Reference
Adenylate kinase motions during catalysis: an energetic counterweight balancing substrate binding., Muller CW, Schlauderer GJ, Reinstein J, Schulz GE, Structure. 1996 Feb 15;4(2):147-56. PMID:8805521
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