title: Purification and properties of an archaebacterial enzyme: citrate synthase from Sulfolobus solfataricus.
abstract: Citrate synthase from the thermoacidophilic archaebacterium Sulfolobus solfataricus was purified to homogeneity. The synthase is a dimer composed of subunits of Mr approximately equal to 40,000. The Km values of acetyl-CoA and oxalacetate are 7 microM and 20 microM, respectively. NADH (Ki = 3.5mM) and ATP (Ki = 0.36mM) are competitive inhibitors vs acetyl-CoA. The dimeric structure and the inhibition by nucleotides (ATP greater than NADH) correlate the archaebacterial enzyme to synthases from eukaryotes and Gram-positive eubacteria.
mesh_terms: D001105:Archaea / Q000201:enzymology*; D001419:Bacteria / Q000201:enzymology*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D002950:Citrate (si)-Synthase / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D007652:Oxo-Acid-Lyases / Q000302:isolation & purification*
chemical_list: D046911:Macromolecular Substances; D002950:Citrate (si)-Synthase; D007652:Oxo-Acid-Lyases