Crystallization and preliminary crystallographic analysis of an NADH oxidase that functions in peroxide reduction in Thermus aquaticus YT-1

NADH oxidase from Thermus aquaticus is a thermostable flavoenzyme that is s imilar in amino-acid sequence and other properties to the flavoenzyme compo nent of the NADH peroxidase systems from Salmonella typhimurium and Amphiba cillus xylanus. The enzyme has been isolated from T. aquaticus and crystall ized using the hanging-drop method of vapour diffusion with sodium citrate as a precipitant at pH 8.5. The crystals belong to the hexagonal space grou p P622 with unit-cell dimensions a = b = 89.9, c = 491.6 Angstrom, and diff ract to 2.5 Angstrom resolution.