2agm
From Proteopedia
(New page: 200px<br /><applet load="2agm" size="450" color="white" frame="true" align="right" spinBox="true" caption="2agm" /> '''Solution structure of the R-module from AlgE...) |
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| - | [[Image:2agm.gif|left|200px]]<br /><applet load="2agm" size=" | + | [[Image:2agm.gif|left|200px]]<br /><applet load="2agm" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2agm" /> | caption="2agm" /> | ||
'''Solution structure of the R-module from AlgE4'''<br /> | '''Solution structure of the R-module from AlgE4'''<br /> | ||
==Overview== | ==Overview== | ||
| - | In the bacterium Azotobacter vinelandii, a family of seven secreted and | + | In the bacterium Azotobacter vinelandii, a family of seven secreted and calcium-dependent mannuronan C-5 epimerases (AlgE1-7) has been identified. These epimerases are responsible for the epimerization of beta-d-mannuronic acid to alpha-l-guluronic acid in alginate polymers. The epimerases consist of two types of structural modules, designated A (one or two copies) and R (one to seven copies). The structure of the catalytically active A-module from the smallest epimerase AlgE4 (consisting of AR) has been solved recently. This paper describes the NMR structure of the R-module from AlgE4 and its titration with a substrate analogue and paramagnetic thulium ions. The R-module folds into a right-handed parallel beta-roll. The overall shape of the R-module is an elongated molecule with a positively charged patch that interacts with the substrate. Titration of the R-module with thulium indicated possible calcium binding sites in the loops formed by the nonarepeat sequences in the N-terminal part of the molecule and the importance of calcium binding for the stability of the R-module. Structure calculations showed that calcium ions can be incorporated in these loops without structural violations and changes. Based on the structure and the electrostatic surface potential of both the A- and R-module from AlgE4, a model for the appearance of the whole protein is proposed. |
==About this Structure== | ==About this Structure== | ||
| - | 2AGM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii]. Full crystallographic information is available from [http:// | + | 2AGM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AGM OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Azotobacter vinelandii]] | [[Category: Azotobacter vinelandii]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Aachmann, F | + | [[Category: Aachmann, F L.]] |
[[Category: Guntert, P.]] | [[Category: Guntert, P.]] | ||
| - | [[Category: Petersen, S | + | [[Category: Petersen, S B.]] |
| - | [[Category: Svanem, B | + | [[Category: Svanem, B I.]] |
[[Category: Valla, S.]] | [[Category: Valla, S.]] | ||
[[Category: Wimmer, R.]] | [[Category: Wimmer, R.]] | ||
[[Category: parallel beta-roll]] | [[Category: parallel beta-roll]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:27:18 2008'' |
Revision as of 14:27, 21 February 2008
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Solution structure of the R-module from AlgE4
Overview
In the bacterium Azotobacter vinelandii, a family of seven secreted and calcium-dependent mannuronan C-5 epimerases (AlgE1-7) has been identified. These epimerases are responsible for the epimerization of beta-d-mannuronic acid to alpha-l-guluronic acid in alginate polymers. The epimerases consist of two types of structural modules, designated A (one or two copies) and R (one to seven copies). The structure of the catalytically active A-module from the smallest epimerase AlgE4 (consisting of AR) has been solved recently. This paper describes the NMR structure of the R-module from AlgE4 and its titration with a substrate analogue and paramagnetic thulium ions. The R-module folds into a right-handed parallel beta-roll. The overall shape of the R-module is an elongated molecule with a positively charged patch that interacts with the substrate. Titration of the R-module with thulium indicated possible calcium binding sites in the loops formed by the nonarepeat sequences in the N-terminal part of the molecule and the importance of calcium binding for the stability of the R-module. Structure calculations showed that calcium ions can be incorporated in these loops without structural violations and changes. Based on the structure and the electrostatic surface potential of both the A- and R-module from AlgE4, a model for the appearance of the whole protein is proposed.
About this Structure
2AGM is a Single protein structure of sequence from Azotobacter vinelandii. Full crystallographic information is available from OCA.
Reference
NMR structure of the R-module: a parallel beta-roll subunit from an Azotobacter vinelandii mannuronan C-5 epimerase., Aachmann FL, Svanem BI, Guntert P, Petersen SB, Valla S, Wimmer R, J Biol Chem. 2006 Mar 17;281(11):7350-6. Epub 2006 Jan 3. PMID:16407237
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