A novel DNA modification discovered in Streptomyces lividans is different from DNA methylation. This unusual modification causes wild type S. lividans DNA sensitive to site-specific oxidative double-strand cleavage (Dnd phenotype, DNA degradation).

• 变铅青链霉菌的DNA异常修饰系统是一种不同于甲基化修饰的新型修饰系统，它可使变铅青链霉菌DNA在电泳时易遭到氧化双链切割(Dnd表型，DNA degradation)(Zhou et al.；1988)。