Rozenfel'd S M, Mironov V A, Zhdanov V G
Genetika. 1982 May;18(5):732-5.
Eremothecium ashbyii mutants resistant to low and high concentrations of 8-azaguanine (AZG), have been obtained. In low resistant mutants (10(-4) M AZG) isolated by one step selection, the activity of GMP- and AMP-pyrophosphorylases was decreased, as compared with the initial sensitive strain. The stepwise increase of the mutants resistance to AZG resulted in increasing of resistance to 8-azaadenine and decreasing of the activity of GMP-pyrophosphorylase, while this did not affect the level of AMP-pyrophosphorylase. Characteristics of the cross-resistance of mutant to purine analogues and the level of nucleotide-pyrophosphorylases activity were discussed in the light of their possible influence on riboflavin biosynthesis.
已获得对低浓度和高浓度8-氮杂鸟嘌呤（AZG）具有抗性的阿舒假囊酵母突变体。在通过一步筛选分离出的低抗性突变体（10⁻⁴ M AZG）中，与初始敏感菌株相比，GMP-焦磷酸化酶和AMP-焦磷酸化酶的活性降低。突变体对AZG抗性的逐步增加导致对8-氮杂腺嘌呤的抗性增加以及GMP-焦磷酸化酶活性降低，而这并不影响AMP-焦磷酸化酶的水平。根据突变体对嘌呤类似物的交叉抗性特征和核苷酸焦磷酸化酶活性水平，对它们可能对核黄素生物合成的影响进行了讨论。
