The structure of the adenosine triphosphate of Thiobacillus thiooxidans.

The adenosine triphosphate3 of Thiobacillus thiooxidans is of special interest because LePage and Umbreit (1943b) presented evidence that it differs from the adenosine triphosphate of other organisms by having the phosphate groups attached to the 3' instead of the 5' position of adenosine. All other bacteria and higher organisms so far examined contain adenosine-5'triphosphate (5'-ATP). Since diphosphopyridine nucleotide, triphosphopyridine nucleotide (Kornberg, 1950), flavin adenine dinucleotide (Schrecker and Kronberg, 1950), and coenzyme A (Novelli, 1953) are known to be formed from adenosine-5'-triphosphate in such a way as to preserve the original ribose-phosphate linkage, the existence of an unusual type of adenosine triphosphate in thiobacilli would imply also the presence of new types of these and probable other nucleotides. Because of the theoretical importance of an unusual type of adenosine triphosphate, a reinvestigation of the compound present in T. thiooxidans seemed desirable, particularly in view of the fact that substantial improvements in the techniques of isolation and characterization of nucleotides have been made in recent years. Our results show that T. thiooxidans con-