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 archaebacterium, 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 designed 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 reading frames was sequenced. Sequence analysis indicated that the sou gene of Acidianus sp. S5 showed 81% identity to the sor gene of Acidianus ambivalens. E. coli cells carrying the sor gene on pBV220SOR were able to overproduce SOR upon a temperature shift from 30 to 42 degreesC. SOR produced in E. coli catalyzes the oxidation of elemental sulfur and concomitant production of sulfite, thiosulfate and hydrogen sulfide. The recombinant enzyme exhibits the same catalytic properties as the one from Acidianus S5. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.