1ru3
From Proteopedia
(New page: 200px<br /><applet load="1ru3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ru3, resolution 2.20Å" /> '''Crystal Structure of...) |
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| - | [[Image:1ru3.jpg|left|200px]]<br /><applet load="1ru3" size=" | + | [[Image:1ru3.jpg|left|200px]]<br /><applet load="1ru3" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ru3, resolution 2.20Å" /> | caption="1ru3, resolution 2.20Å" /> | ||
'''Crystal Structure of the monomeric acetyl-CoA synthase from Carboxydothermus hydrogenoformans'''<br /> | '''Crystal Structure of the monomeric acetyl-CoA synthase from Carboxydothermus hydrogenoformans'''<br /> | ||
==Overview== | ==Overview== | ||
| - | In anaerobic microorganisms employing the acetyl-CoA pathway, acetyl-CoA | + | In anaerobic microorganisms employing the acetyl-CoA pathway, acetyl-CoA synthase (ACS) and CO dehydrogenase (CODH) form a complex (ACS/CODH) that catalyzes the synthesis of acetyl-CoA from CO, a methyl group, and CoA. Previously, a [4Fe-4S] cubane bridged to a copper-nickel binuclear site (active site cluster A of the ACS component) was identified in the ACS(Mt)/CODH(Mt) from Moorella thermoacetica whereas another study revealed a nickel-nickel site in the open form of ACS(Mt), and a zink-nickel site in the closed form. The ACS(Ch) of the hydrogenogenic bacterium Carboxydothermus hydrogenoformans was found to exist as an 82.2-kDa monomer as well as in a 1:1 molar complex with the 73.3-kDa CODHIII(Ch). Homogeneous ACS(Ch) and ACS(Ch)/CODHIII(Ch) catalyzed the exchange between [1-(14)C]acetyl-CoA and (12)CO with specific activities of 2.4 or 5.9 micromol of CO per min per mg, respectively, at 70 degrees C and pH 6.0. They also catalyzed the synthesis of acetyl-CoA from CO, methylcobalamin, corrinoid iron-sulfur protein, and CoA with specific activities of 0.14 or 0.91 micromol of acetyl-CoA formed per min per mg, respectively, at 70 degrees C and pH 7.3. The functional cluster A of ACS(Ch) contains a Ni-Ni-[4Fe-4S] site, in which the positions proximal and distal to the cubane are occupied by Ni ions. This result is apparent from a positive correlation of the Ni contents and negative correlations of the Cu or Zn contents with the acetyl-CoA/CO exchange activities of different preparations of monomeric ACS(Ch), a 2.2-A crystal structure of the dithionite-reduced monomer in an open conformation, and x-ray absorption spectroscopy. |
==About this Structure== | ==About this Structure== | ||
| - | 1RU3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Carboxydothermus_hydrogenoformans Carboxydothermus hydrogenoformans] with NI, SF4 and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1RU3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Carboxydothermus_hydrogenoformans Carboxydothermus hydrogenoformans] with <scene name='pdbligand=NI:'>NI</scene>, <scene name='pdbligand=SF4:'>SF4</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RU3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: nickel]] | [[Category: nickel]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:54:35 2008'' |
Revision as of 12:54, 21 February 2008
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Crystal Structure of the monomeric acetyl-CoA synthase from Carboxydothermus hydrogenoformans
Overview
In anaerobic microorganisms employing the acetyl-CoA pathway, acetyl-CoA synthase (ACS) and CO dehydrogenase (CODH) form a complex (ACS/CODH) that catalyzes the synthesis of acetyl-CoA from CO, a methyl group, and CoA. Previously, a [4Fe-4S] cubane bridged to a copper-nickel binuclear site (active site cluster A of the ACS component) was identified in the ACS(Mt)/CODH(Mt) from Moorella thermoacetica whereas another study revealed a nickel-nickel site in the open form of ACS(Mt), and a zink-nickel site in the closed form. The ACS(Ch) of the hydrogenogenic bacterium Carboxydothermus hydrogenoformans was found to exist as an 82.2-kDa monomer as well as in a 1:1 molar complex with the 73.3-kDa CODHIII(Ch). Homogeneous ACS(Ch) and ACS(Ch)/CODHIII(Ch) catalyzed the exchange between [1-(14)C]acetyl-CoA and (12)CO with specific activities of 2.4 or 5.9 micromol of CO per min per mg, respectively, at 70 degrees C and pH 6.0. They also catalyzed the synthesis of acetyl-CoA from CO, methylcobalamin, corrinoid iron-sulfur protein, and CoA with specific activities of 0.14 or 0.91 micromol of acetyl-CoA formed per min per mg, respectively, at 70 degrees C and pH 7.3. The functional cluster A of ACS(Ch) contains a Ni-Ni-[4Fe-4S] site, in which the positions proximal and distal to the cubane are occupied by Ni ions. This result is apparent from a positive correlation of the Ni contents and negative correlations of the Cu or Zn contents with the acetyl-CoA/CO exchange activities of different preparations of monomeric ACS(Ch), a 2.2-A crystal structure of the dithionite-reduced monomer in an open conformation, and x-ray absorption spectroscopy.
About this Structure
1RU3 is a Single protein structure of sequence from Carboxydothermus hydrogenoformans with , and as ligands. Full crystallographic information is available from OCA.
Reference
A functional Ni-Ni-[4Fe-4S] cluster in the monomeric acetyl-CoA synthase from Carboxydothermus hydrogenoformans., Svetlitchnyi V, Dobbek H, Meyer-Klaucke W, Meins T, Thiele B, Romer P, Huber R, Meyer O, Proc Natl Acad Sci U S A. 2004 Jan 13;101(2):446-51. Epub 2003 Dec 29. PMID:14699043
Page seeded by OCA on Thu Feb 21 14:54:35 2008
Categories: Carboxydothermus hydrogenoformans | Single protein | Dobbek, H. | Huber, R. | Meins, T. | Meyer, O. | Meyer-Klaucke, W. | Rmer, P. | Svetlitchnyi, V. | Thiele, B. | GOL | NI | SF4 | Cluster a | Nickel
