The accumulation of orotic acid by a pyrimidineless mutant of Neurospora

The discovery of orotic acid (1,2-carboxyuracil) in cow's milk by Biscaro and Belloni (1), followed by its identification and synthesis (2-4), led to a number of speculations as to its biological origin and significance (,3,5,6). A definite connection of orotic acid with the biosynthesis of nucleic acid pyrimidines is provided by the finding that orotic acid (7) as well as thymine (8,9) can supplement or replace the folic acid required by certain microorganisms. As suggested by Chattaway (7), it would appear that folic acid has a function in the biosynthesis of pyrimidines. Furthermore, this function is probably concerned in some step prior to the appearance of orotic acid in the biosynthetic series. More recently it was shown by Loring and Pierce (10) that orotic acid could be substituted for uracil in satisfying the growth requirements of some pyrimidineless mutants of the mold Neurospora. Investigations of orotic acid in this laboratory have led to a new method of synthesis of the compound (11) and to some suggestions concerning its relation to the biosynthesis of nucleic acids in Neurospora (12). The results of the present work are in accord with the previous suggestions and provide further evidence on the biological origin and function of orotic acid

WElegal|Clinic

https://larc.cardozo.yu.edu/event-invitations-2018/1046/thumbnail.jp

The use of isotopic carbon in a study of the metabolism of anthanilic acid in Neurospora

The finding by Tatum, Banner, and Beadle (l), that the tryptophanless Neurospora mutant strain 10575 accumulates anthranilic acid, which in turn can be utilized for growth of strain 40008, has provided evidence that anthranilic acid is a biochemical precursor of tryptophan in this organism. It has been further established that indole is an intermediate in this conversion (2-5). More recent work with a number of mutants of Neurospora (6-8) has established that tryptophan is a biochemical precursor to niacin with kynurenine and hydroxyanthranilic acid as intermediates. The accumulated evidence has indicated the existence in the mold of the following series of reactions: → Anthranilic acid → indole → tryptophan → kynurenine → 3-hydroxyanthranilic acid → nicotinic acid In the light of this evidence the present work was undertaken to trace the carbon in the carboxyl group of anthranilic acid in order to estimate its contribution as a structural unit in the formation of niacin and tryptophan. The organism chosen for this investigation was a biochemical mutant strain of Neurospora designated as strain 40008. This mutant utilizes anthranilic acid, indole, or tryptophan for growth. The mutant was grown in the presence of anthranilic acid containing Cl4 in the carboxyl group. Niacin and tryptophan were isolated from the mold mycelium and tested for radioactivity

Lecture 6: Mobile Application and Product Development

Lecture for the course CSCI 380 - Mobile Application and Product Development delivered at John Jay College in Spring 2019 by Bhargava Chinthirla and Eric Spector as part of the Tech-in-Residence Corps program

Intro to Data Science - Course Intro (Week One)

Lecture for the course CSC 59970: Intro to Data Science (Week One) delivered at the City College of New York in Fall 2018 by Grant Long as part of the Tech-in-Residence Corps program

Homework 2: Intro to Data Science ( Week Two)

Homework assignment for the course CSC 59970: Intro to Data Science (Week Two) delivered at the City College of New York in Fall 2018 by Grant Long as part of the Tech-in-Residence Corps program

Homework 1: Intro to Data Science (Week One)

Homework assignment for the course CSC 59970: Intro to Data Science (Week One) delivered at the City College of New York in Fall 2018 by Grant Long as part of the Tech-in-Residence Corps program