2h12

Structure of Acetobacter aceti citrate synthase complexed with oxaloacetate and carboxymethyldethia coenzyme A (CMX)

spinqualitylabelsall models 2h12, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2h12 is a 6 chain structure with sequence from Acetobacter aceti. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.85Å Ligands: CMX, OAA, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CISY_ACEAC Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Acetobacter aceti converts ethanol to acetic acid, and strains highly resistant to both are used to make vinegar. A. aceti survives acetic acid exposure by tolerating cytoplasmic acidification, which implies an unusual adaptation of cytoplasmic components to acidic conditions. A. aceti citrate synthase (AaCS), a hexameric type II citrate synthase, is required for acetic acid resistance and, therefore, would be expected to function at low pH. Recombinant AaCS has intrinsic acid stability that may be a consequence of strong selective pressure to function at low pH, and unexpectedly high thermal stability for a protein that has evolved to function at approximately 30 degrees C. The crystal structure of AaCS, complexed with oxaloacetate (OAA) and the inhibitor carboxymethyldethia-coenzyme A (CMX), was determined to 1.85 A resolution using protein purified by a tandem affinity purification procedure. This is the first crystal structure of a "closed" type II CS, and its active site residues interact with OAA and CMX in the same manner observed in the corresponding type I chicken CS.OAA.CMX complex. While AaCS is not regulated by NADH, it retains many of the residues used by Escherichia coli CS (EcCS) for NADH binding. The surface of AaCS is abundantly decorated with basic side chains and has many fewer uncompensated acidic charges than EcCS; this constellation of charged residues is stable in varied pH environments and may be advantageous in the A. aceti cytoplasm. Structure of a NADH-insensitive hexameric citrate synthase that resists acid inactivation.,Francois JA, Starks CM, Sivanuntakorn S, Jiang H, Ransome AE, Nam JW, Constantine CZ, Kappock TJ Biochemistry. 2006 Nov 14;45(45):13487-99. PMID:17087502 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Citrate Synthase 3D structures

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