Cloning and heterologous expression of a sulfur oxygenase/reductase gene from the thermoacidophilic archaeon Acidianus sp S5 in Escherichia coli

A thermoacidophilic, obligately chemolithotrophic. facultatively aerobic ar chaebacterium, Acidianus sp. S5. was isolated from acidothermal springs in southwest China. The sulfur oxygenase/reductase (SOR) gene of Acidianus sp. S5 was cloned and expressed in Escherichia coli. Several primers were desi gned and successfully applied for detection and cloning of the sor gene. A 3.7-kb EcoRI fragment containing the sor gene and three neighboring open re ading frames was sequenced. Sequence analysis indicated that the sou gene o f Acidianus sp. S5 showed 81% identity to the sor gene of Acidianus ambival ens. E. coli cells carrying the sor gene on pBV220SOR were able to overprod uce SOR upon a temperature shift from 30 to 42 degreesC. SOR produced in E. coli catalyzes the oxidation of elemental sulfur and concomitant productio n of sulfite, thiosulfate and hydrogen sulfide. The recombinant enzyme exhi bits the same catalytic properties as the one from Acidianus S5. (C) 2000 F ederation of European Microbiological Societies. Published by Elsevier Scie nce B.V. All rights reserved.