Formation of 4-Amino-5-Carboxamidoimidazole During Growth of Escherichia Coli in the Presence of 4-Aminopteroylglutamic Acid

Inhibition by Biotin of Desthiobiotin Production in Bacillus Cereus

“…Actithiazic acid would compete at the site for the inhibition by biotin or inhibit the synthesis of biotin; in either case it would cause the production of desthiobiotin at the activated rate. This result may be comparable with the observations that microorganisms grown in the presence of antimetabolites excrete the precursors of the metabolites (23)(24)(25)(26), though the excretions do not occur in the absence of antimetabolites in such cases, while it did in this case. The increased excretion of nicotinic acid in mutants of Chlamydomonas eugametos (27) resistant to 3-acetyl pyridine may be in a similar case.…”

Aminopterin inhibition in Aerobacter aerogenes: alanine and valine accumulation during the inhibition and their utilization on recovery

“…The accumulation of the imidazole derivative by A. aerogene8 is in accordance with previous findings in E. coli (Woolley & Pringle, 1950;Edwards et al 1952), and the known inhibition by the folic acid antagonists of the incorporation of formate into nucleic acid purines (Skipper, Mitchell & Bennett, 1950;Goldthwait & Bendich, 1952). In the present system, however, there is an inhibition not only of the incorporation, but also of the production of formate.…”

“…The prevention by adenine both of the growth inhibition and the production of alanine and valine in the treated cultures, when considered together with the decreased deoxyribonucleic acid content of the cells (Table 1), suggested the possibility of a relationship between amino acid accumulation and inhibition of purine synthesis. In cultures of certain bacteria inhibition of purine synthesis by the folic acid antagonists, as well as by sulphonamides, is known to result in the accumulation of 5-amino-4-imidazolecarboxamide riboside (Woolley & Pringle, 1950;Edwards, Skipper & Johnson, 1952;Stetten & Fox 1945;Ravel et al 1948;Greenberg, 1952). In previous work (Webb, 1955) attempts to demonstrate the presence of this imidazole derivative in cultures of A. aerogenes after recovery from inhibition by aminopterin were unsuccessful.…”

Studies on the biosynthesis of riboflavin. 2. Further observations on nitrogen metabolism and flavinogenesis in Eremothecium ashbyii

“…Aminopterin was examined for its effect on riboflavin synthesis because of its known inhibitory effect on the biosynthesis of purines (Woolley & Pringle, 1950;Buchanan & Wilson, 1953). Fig.…”

“…The inhibition of growth of E. a8hbyii by aminopterin, which is counteracted by folinic acid, agrees with the established picture of the function of this inhibitor. Aminopterin appears to act in purine biosynthesis by inhibiting the incorporation of a one-carbon unit into C2, for Woolley & Pringle (1950) found that 4-amino-5-imidazolecarboxamide (4(5)-amino-5(4)-carbamoylglyoxaline) (III) accumulated in aminopterin-inhibited cultures of E8cherichia coli. No evidence has yet appeared that the probable acycic precursor (IV), or its ribotide (Greenberg, 1953), of the imidazolecarboxamide also accumulates, although the insertion of C8 to form the imidazole is also mediated through a one carbon fragment.…”