Institute of Biochemistry and Biophysics of the Polish Academy of Sciences, 02-106 Warsaw, Poland.
Department of Epidemiology and Clinical Microbiology, National Medicines Institute, 00-725 Warsaw, Poland.
Viruses. 2020 Mar 7;12(3):292. doi: 10.3390/v12030292.
Staphylococcal bacteriophages of the genus are candidates for therapeutic applications. One of their proteins, Tgl, is slightly similar to two staphylococcal virulence factors, secreted autolysins of lytic transglycosylase motifs IsaA and SceD. We show that Tgl is a lytic enzyme secreted by the bacterial transport system and localizes to cell peripheries like IsaA and SceD. It causes lysis of cells expressing the cloned gene, but could be overproduced when depleted of signal peptide. cells producing Tgl lysed in the presence of nisin, which mimics the action of phage holin. In vitro, Tgl protein was able to destroy cell walls. The production of Tgl decreased tolerance to vancomycin, unlike the production of SceD, which is associated with decreased sensitivity to vancomycin. In the genomes of kayviruses, the gene is located a few genes away from the gene, encoding the major endolysin. While is a late phage gene, can be transcribed by a host RNA polymerase, like phage early genes. Taken together, our data indicate that belongs to the kayvirus lytic module and encodes an additional endolysin that can act in concert with LysK in cell lysis.
葡萄球菌噬菌体属的噬菌体是治疗应用的候选者。它们的一种蛋白质 Tgl 与两种葡萄球菌毒力因子——具有裂解转糖基酶基序的分泌自溶素 IsaA 和 SceD 略有相似。我们表明，Tgl 是一种由细菌转运系统分泌的溶酶，与 IsaA 和 SceD 一样定位于细胞外周。它导致表达克隆基因的细胞裂解，但当信号肽缺失时可以过量产生。产生 Tgl 的细胞在乳链菌肽存在下裂解，乳链菌肽模拟噬菌体 holin 的作用。在体外，Tgl 蛋白能够破坏细胞壁。与 SceD 不同，Tgl 的产生降低了对万古霉素的耐受性，而 SceD 的产生与对万古霉素的敏感性降低有关。在 kayviruses 的基因组中，基因位于编码主要内溶素的基因几处。虽然是晚期噬菌体基因，但可以像噬菌体早期基因一样由宿主 RNA 聚合酶转录。总的来说，我们的数据表明属于 kayvirus 裂解模块，并编码一种额外的内溶素，它可以与 LysK 协同作用在细胞裂解中。
