1b8v: Difference between revisions

Revision as of 12:52, 21 February 2008

Malate dehydrogenase from Aquaspirillum arcticum

OverviewOverview

Aquaspillium arcticum is a psychrophilic bacterium that was isolated from arctic sediment and grows optimally at 4 degrees C. We have cloned, purified, and characterized malate dehydrogenase from A. arcticum (Aa MDH). We also have determined the crystal structures of apo-Aa MDH, Aa MDH.NADH binary complex, and Aa MDH.NAD.oxaloacetate ternary complex at 1.9-, 2.1-, and 2.5-A resolutions, respectively. The Aa MDH sequence is most closely related to the sequence of a thermophilic MDH from Thermus flavus (Tf MDH), showing 61% sequence identity and over 90% sequence similarity. Stability studies show that Aa MDH has a half-life of 10 min at 55 degrees C, whereas Tf MDH is fully active at 90 degrees C for 1 h. Aa MDH shows 2-3-fold higher catalytic efficiency compared with a mesophilic or a thermophilic MDH at the temperature range 4-10 degrees C. Structural comparison of Aa MDH and Tf MDH suggests that the increased relative flexibility of active site residues, favorable surface charge distribution for substrate and cofactor, and the reduced intersubunit ion pair interactions may be the major factors for the efficient catalytic activity of Aa MDH at low temperatures.

About this StructureAbout this Structure

1B8V is a Single protein structure of sequence from Aquaspirillum arcticum with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Structural basis for cold adaptation. Sequence, biochemical properties, and crystal structure of malate dehydrogenase from a psychrophile Aquaspirillium arcticum., Kim SY, Hwang KY, Kim SH, Sung HC, Han YS, Cho Y, J Biol Chem. 1999 Apr 23;274(17):11761-7. PMID:10206992

Page seeded by OCA on Thu Feb 21 11:52:43 2008

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OCA

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-[[Image:1b8v.gif|left|200px]]<br /><applet load="1b8v" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1b8v.gif|left|200px]]<br /><applet load="1b8v" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1b8v, resolution 2.1&Aring;" />
 '''Malate dehydrogenase from Aquaspirillum arcticum'''<br />
 ==Overview==
-Aquaspillium arcticum is a psychrophilic bacterium that was isolated from, arctic sediment and grows optimally at 4 degrees C. We have cloned, purified, and characterized malate dehydrogenase from A. arcticum (Aa, MDH). We also have determined the crystal structures of apo-Aa MDH, Aa, MDH.NADH binary complex, and Aa MDH.NAD.oxaloacetate ternary complex at, 1.9-, 2.1-, and 2.5-A resolutions, respectively. The Aa MDH sequence is, most closely related to the sequence of a thermophilic MDH from Thermus, flavus (Tf MDH), showing 61% sequence identity and over 90% sequence, similarity. Stability studies show that Aa MDH has a half-life of 10 min, at 55 degrees C, whereas Tf MDH is fully active at 90 degrees C for 1 h., Aa MDH shows 2-3-fold higher catalytic efficiency compared with a, mesophilic or a thermophilic MDH at the temperature range 4-10 degrees C., Structural comparison of Aa MDH and Tf MDH suggests that the increased, relative flexibility of active site residues, favorable surface charge, distribution for substrate and cofactor, and the reduced intersubunit ion, pair interactions may be the major factors for the efficient catalytic, activity of Aa MDH at low temperatures.
+Aquaspillium arcticum is a psychrophilic bacterium that was isolated from arctic sediment and grows optimally at 4 degrees C. We have cloned, purified, and characterized malate dehydrogenase from A. arcticum (Aa MDH). We also have determined the crystal structures of apo-Aa MDH, Aa MDH.NADH binary complex, and Aa MDH.NAD.oxaloacetate ternary complex at 1.9-, 2.1-, and 2.5-A resolutions, respectively. The Aa MDH sequence is most closely related to the sequence of a thermophilic MDH from Thermus flavus (Tf MDH), showing 61% sequence identity and over 90% sequence similarity. Stability studies show that Aa MDH has a half-life of 10 min at 55 degrees C, whereas Tf MDH is fully active at 90 degrees C for 1 h. Aa MDH shows 2-3-fold higher catalytic efficiency compared with a mesophilic or a thermophilic MDH at the temperature range 4-10 degrees C. Structural comparison of Aa MDH and Tf MDH suggests that the increased relative flexibility of active site residues, favorable surface charge distribution for substrate and cofactor, and the reduced intersubunit ion pair interactions may be the major factors for the efficient catalytic activity of Aa MDH at low temperatures.
 ==About this Structure==
-B8V is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aquaspirillum_arcticum Aquaspirillum arcticum] with NAD as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1B8V OCA].
+B8V is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aquaspirillum_arcticum Aquaspirillum arcticum] with <scene name='pdbligand=NAD:'>NAD</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B8V OCA].
 ==Reference==
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 [[Category: Single protein]]
 [[Category: Cho, Y.]]
-[[Category: Han, Y.S.]]
+[[Category: Han, Y S.]]
-[[Category: Hwang, K.Y.]]
+[[Category: Hwang, K Y.]]
-[[Category: Kim, S.H.]]
+[[Category: Kim, S H.]]
-[[Category: Kim, S.Y.]]
+[[Category: Kim, S Y.]]
 [[Category: NAD]]
 [[Category: dehydrogenase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 11:27:53 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:52:43 2008''