Sisto Ian, Ely Bert
Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
Viruses. 2025 Feb 25;17(3):311. doi: 10.3390/v17030311.
Bacteriophages grown on strain CB15 have reduced plating efficiency on other strains. To determine the cause of this reduced plating efficiency, we performed a series of experiments that demonstrated that the reduced plating efficiency is due to a novel set of restriction and modification (RM) enzymes that are present in most of the strains that we tested. We then demonstrated that one of these RM systems recognizes the nucleotide sequence 5'-ATNNAT-3'. A careful inspection of the genome nucleotide sequences of each of the strains revealed that the genes coding for these RM enzymes have not been annotated or identified, suggesting that the proteins may differ from the common types of bacterial restriction and modification enzymes. In addition, the host strain NA1000 contains a 26 kb mobile element that provides resistance to incoming phages.
在CB15菌株上生长的噬菌体在其他菌株上的平板接种效率降低。为了确定这种平板接种效率降低的原因，我们进行了一系列实验，结果表明平板接种效率降低是由于我们测试的大多数菌株中存在一组新的限制与修饰（RM）酶。然后我们证明了这些RM系统之一识别核苷酸序列5'-ATNNAT-3'。对每个菌株的基因组核苷酸序列进行仔细检查后发现，编码这些RM酶的基因尚未被注释或鉴定，这表明这些蛋白质可能不同于常见类型的细菌限制与修饰酶。此外，宿主菌株NA1000含有一个26 kb的移动元件，可对进入的噬菌体产生抗性。
