1RU3

Crystal Structure of the monomeric acetyl-CoA synthase from Carboxydothermus hydrogenoformans

Summary for 1RU3

• Entry DOI: 10.2210/pdb1ru3/pdb
• Descriptor: Acetyl-CoA synthase, NICKEL (II) ION, IRON/SULFUR CLUSTER, ... (5 entities in total)
• Functional Keywords: nickel, cluster a, oxidoreductase
• Biological source: Carboxydothermus hydrogenoformans
• Total number of polymer chains: 1
• Total formula weight: 83887.57

Authors

Svetlitchnyi, V.,Dobbek, H.,Meyer-Klaucke, W.,Meins, T.,Thiele, B.,Rmer, P.,Huber, R.,Meyer, O. (deposition date: 2003-12-11, release date: 2003-12-23, Last modification date: 2024-10-30)

Primary citation

Svetlitchnyi, V.,Dobbek, H.,Meyer-Klaucke, W.,Meins, T.,Thiele, B.,Rmer, P.,Huber, R.,Meyer, O.
A functional Ni-Ni-[4Fe-4S] cluster in the monomeric acetyl-CoA synthase from Carboxydothermus hydrogenoformans
Proc.Natl.Acad.Sci.USA, 101:446-451, 2004

PubMed Abstract: 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.

PubMed: 14699043
DOI: 10.1073/pnas.0304262101

Experimental method

X-RAY DIFFRACTION (2.2 Å)