[Structural and functional analysis of enzymes and their application to clinical analysis--study on Pseudomonas putida formaldehyde dehydrogenase].
Formaldehyde dehydrogenase (PFDH) was isolated from the creatinine-decomposing bacterium Pseudomonas putida, and its gene has been cloned. PFDH is unique because it was the only enzyme that catalyzed the dehydrogenation of formaldehyde without glutathione. PFDH belongs to a zinc-containing alcohol dehydrogenase family. Quantitative analysis of the reaction products using NMR revealed that the enzyme is not simply a dehydrogenase but is an aldehyde dismutase catalyzing a simultaneous conversion of both aldehyde to carboxylate and aldehyde to alcohol. The enzyme contains a tightly bound cofactor of NAD+/NADH per subunit and is classified as a nicotinoprotein. The enzyme reaction can proceed without external addition of the nucleotide cofactor. The formaldehyde was crystallized using the hanging-drop vapor diffusion method with ammonium sulfate as a precipitant. The crystal structure was determined using the multiwavelength anomalous diffraction method with intrinsic zinc ions. The overall structure of PFDH is similar to that of a classic horse liver alcohol dehydrogenase. However, a comparison of these structures indicated that the insertion loop specifically found in PFDH may be responsible for the tight binding of the cofactor, thereby making PFDH a dismutase.
Ito
Kiyoshi
K
Department of Molecular Medicinal Sciences, Division of Biotechnology, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan. k-ito@cc.nagasaki-u.ac.jp
D000445:Aldehyde Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002384:Catalysis; D003001:Cloning, Molecular; D003404:Creatinine / Q000032:analysis; D018360:Crystallography, X-Ray; D007677:Kidney Function Tests; D008969:Molecular Sequence Data; D016958:Pseudomonas putida / Q000201:enzymology*; D016415:Sequence Alignment; D013379:Substrate Specificity
D015415:Biomarkers; D003404:Creatinine; D000445:Aldehyde Oxidoreductases; C087006:formaldehyde dehydrogenase, glutathione-independent