1ys4: Difference between revisions

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New page: left|200px<br /><applet load="1ys4" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ys4, resolution 2.29Å" /> '''Structure of Asparta...
 
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[[Image:1ys4.jpg|left|200px]]<br /><applet load="1ys4" size="450" color="white" frame="true" align="right" spinBox="true"  
[[Image:1ys4.jpg|left|200px]]<br /><applet load="1ys4" size="350" color="white" frame="true" align="right" spinBox="true"  
caption="1ys4, resolution 2.29&Aring;" />
caption="1ys4, resolution 2.29&Aring;" />
'''Structure of Aspartate-Semialdehyde Dehydrogenase from Methanococcus jannaschii'''<br />
'''Structure of Aspartate-Semialdehyde Dehydrogenase from Methanococcus jannaschii'''<br />


==Overview==
==Overview==
The structure of aspartate-beta-semialdehyde dehydrogenase (ASADH) from, Methanococcus jannaschii has been determined to 2.3 angstroms resolution, using multiwavelength anomalous diffraction (MAD) phasing of a, selenomethionine-substituted derivative to define a new branch in the, family of ASADHs. This new structure has a similar overall fold and domain, organization despite less than 10% conserved sequence identity with the, bacterial enzymes. However, the entire repertoire of functionally, important active site amino acid residues is conserved, suggesting an, identical catalytic mechanism but with lower catalytic efficiency. A new, coenzyme-binding conformation and dual NAD/NADP coenzyme specificity, further distinguish this archaeal branch from the bacterial ASADHs., Several structural differences are proposed to account for the, dramatically enhanced thermostability of this archaeal enzyme. Finally, the intersubunit communication channel connecting the active sites in the, bacterial enzyme dimer has been disrupted in the archaeal ASADHs by amino, acid changes that likely prevent the alternating sites reactivity, previously proposed for the bacterial ASADHs.
The structure of aspartate-beta-semialdehyde dehydrogenase (ASADH) from Methanococcus jannaschii has been determined to 2.3 angstroms resolution using multiwavelength anomalous diffraction (MAD) phasing of a selenomethionine-substituted derivative to define a new branch in the family of ASADHs. This new structure has a similar overall fold and domain organization despite less than 10% conserved sequence identity with the bacterial enzymes. However, the entire repertoire of functionally important active site amino acid residues is conserved, suggesting an identical catalytic mechanism but with lower catalytic efficiency. A new coenzyme-binding conformation and dual NAD/NADP coenzyme specificity further distinguish this archaeal branch from the bacterial ASADHs. Several structural differences are proposed to account for the dramatically enhanced thermostability of this archaeal enzyme. Finally, the intersubunit communication channel connecting the active sites in the bacterial enzyme dimer has been disrupted in the archaeal ASADHs by amino acid changes that likely prevent the alternating sites reactivity previously proposed for the bacterial ASADHs.


==About this Structure==
==About this Structure==
1YS4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanocaldococcus_jannaschii Methanocaldococcus jannaschii] with NAP and MLA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate-semialdehyde_dehydrogenase Aspartate-semialdehyde dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.2.1.11 1.2.1.11] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1YS4 OCA].  
1YS4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanocaldococcus_jannaschii Methanocaldococcus jannaschii] with <scene name='pdbligand=NAP:'>NAP</scene> and <scene name='pdbligand=MLA:'>MLA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate-semialdehyde_dehydrogenase Aspartate-semialdehyde dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.2.1.11 1.2.1.11] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YS4 OCA].  


==Reference==
==Reference==
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[[Category: Methanocaldococcus jannaschii]]
[[Category: Methanocaldococcus jannaschii]]
[[Category: Single protein]]
[[Category: Single protein]]
[[Category: Faehnle, C.R.]]
[[Category: Faehnle, C R.]]
[[Category: Ohren, J.F.]]
[[Category: Ohren, J F.]]
[[Category: Viola, R.E.]]
[[Category: Viola, R E.]]
[[Category: MLA]]
[[Category: MLA]]
[[Category: NAP]]
[[Category: NAP]]
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[[Category: oxidoreductase]]
[[Category: oxidoreductase]]


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