Utilization of Methylthio-s-Triazine for Growth of Soil Fungi

Aspergillus niger van Tieghem, Aspergillus tamarii Kita, and Aspergillus flavus Link ex Fries utilized the methylthio moiety of 2,4-bis(isopropylamino) -6-methyl-mercapto-s-triazine (prometryne) as a sulfur nutrient source. Other soil fungal isolates not affected by prometryne concentrations to 1 mg/ml culture included: Aspergillus oryzae (Ahlburg) Cohn, Curvularia lunata (Wakker) Boedijn, Trichoderma viride Persoon ex Fries, Alternaria tenuis Nees ex Corda, Penicillium funiculosum Thom, and Paecilomyces varioti Bainier.     

Nucleotide sequences at the sites of action of the deoxyribonucleic acid modification enzyme of bacteriophage P1

Labelled oligonucleotides have been fractionated from DNAase digests of phage λ DNA that had been methylated with the phage P1 modification enzyme and S-[methyl-¹⁴C]adenosyl-l-methionine. The longest sequences established are the tetranucleotides pG-ǎ?-T-C4 and p?-T-C-T, which, together with the other sequences determined, particularly pA-G-?, show that the modification enzyme, M.EcoP1, methylates adenine residues within defined sequences and suggest that the oligonucleotide sequence recognized by this enzyme is the hexanucleotide pA-G-A-T-C-T. The duplex formed by base-pairing this hexanucleotide with its complementary sequence resembles the recognition sequence for several restriction enzymes in being bisected by an axis of 2-fold rotational symmetry.