title: Azotobacter vinelandii citrate synthase.
abstract: We have purified the citrate synthase from Azotobacter vinelandii and have determined that the size of the subunit is 48,000 Da and the structure of the holoenzyme is a hexamer. This contrasts with earlier estimates that indicate a 58,000 Da subunit and a tetrameric structure. In addition, the enzyme is allosteric with a Hill coefficient of 1.5 and is inhibited by NADH. The Hill coefficient is changed to about 1 by high ionic strength and AMP. The enzyme is thus similar to the citrate synthases of many other Gram-negative, facultative, anaerobic organisms. In addition, the amino acid sequence of about 100 residues has been determined and found to be highly similar to the sequence of Pseudomonas aeruginosa citrate synthase.
authors: Pre-Clinical Science Unit, Department of Veterans Affairs Medical Center, Dallas, Texas 75216.
authors: M
authors: M
authors: Rault-Leonardon
authors: M A
authors: MA
authors: Atkinson
authors: C A
authors: CA
authors: Slaughter
authors: C R
authors: CR
authors: Moomaw
authors: P A
authors: PA
authors: Srere
mesh_terms: D000595:Amino Acid Sequence; D016948:Azotobacter vinelandii / Q000201:enzymology*; D002950:Citrate (si)-Synthase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009243:NAD / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D014461:Ultracentrifugation
chemical_list: D009243:NAD; D002950:Citrate (si)-Synthase