Shivakumar A G, Dubnau D
J Bacteriol. 1978 Dec;136(3):1205-7. doi: 10.1128/jb.136.3.1205-1207.1978.
The replication in Bacillus subtilis of the staphylococcal R plasmids pE194, pBD15, pUB110, pSA0501, and pSA2100 has been studied in the presence of hydroxyurea. In all cases, an enrichment for covalently closed circular DNA compared with chromosomal DNA was observed. In this respect, hydroxyurea mimics the effect previously observed with pUB110, using strains carrying the conditional mutation dnaA13. This mutation has been reported to affect ribonucleotide reductase (G. W. Bazill and D. Karamata, Mol. Gen. Genet. 117:19-29, 1972). An explanation for these effects is offered, together with some supporting evidence.
在羟基脲存在的情况下，对葡萄球菌R质粒pE194、pBD15、pUB110、pSA0501和pSA2100在枯草芽孢杆菌中的复制进行了研究。在所有情况下，均观察到与染色体DNA相比，共价闭合环状DNA出现富集。在这方面，羟基脲模拟了之前使用携带条件突变dnaA13的菌株对pUB110所观察到的效应。据报道，这种突变会影响核糖核苷酸还原酶（G. W. 巴齐尔和D. 卡拉马塔，《分子与普通遗传学》117:19 - 29，1972年）。文中给出了这些效应的一种解释以及一些支持证据。
