Studies of the biosynthesis of orotic acid.

* The data in this paper have been taken from a thesis presented by Ray Wu to the Graduate School of Arts and Sciences of the University of Pennsylvania in partial fulfilment of the requirements for the degree of Doctor of Philosophy. An abstract of a preliminary report of this work has appeared (1). Aided by a grant from the American Cancer Society, administered by the Committee on Growth of the National Research Council, and by a grant from the Atomic Energy Commission. t Present address, Public Health Research Institute of The City of New York, Foot of East 15th Street, New York. 1 The following abbreviations are used in the present paper: AD, alcohol dehydrogenase; ASU, acid-soluble uracil; ATP, adenosine triphosphate; CoA, coenzyme A; DPN, diphosphopyridine nucleotide; DPNH, reduced DPN; DHO, dihydroorotic acid; FDP, fructose-1,6-diphosphate; OA, erotic acid; TCA, trichloroacetic acid; TPN, triphosphopyridine nucleotide; US, ureidosuccinic acid.