Department of Biological Sciences, University of Alberta, CW 405 Biological Sciences Building, Edmonton, AB T6G 2E9, Canada.
Viruses. 2022 Apr 29;14(5):938. doi: 10.3390/v14050938.
Bacteriophage JC1 is a phage with a C1 morphotype, isolated on host strain Van1. Phage JC1 is capable of infecting an expansive range of complex (Bcc) species. The JC1 genome exhibits significant similarity and synteny to Bcep22-like phages and to many phages. The genome of JC1 was determined to be 61,182 bp in length with a 65.4% G + C content and is predicted to encode 76 proteins and 1 tRNA gene. Unlike the other , JC1 encodes a putative helicase gene in its replication module, and it is in a unique organization not found in previously analyzed phages. The JC1 genome also harbours 3 interesting moron genes, that encode a carbon storage regulator (CsrA), an N-acetyltransferase, and a phosphoadenosine phosphosulfate (PAPS) reductase. JC1 can stably lysogenize its host Van1 and integrates into the 5' end of the gene . This is the first account of stable integration identified for Bcep22-like phages. JC1 has a higher global virulence index at 37 °C than at 30 °C (0.8 and 0.21, respectively); however, infection efficiency and lysogen stability are not affected by a change in temperature, and no observable temperature-sensitive switch between lytic and lysogenic lifestyle appears to exist. Although JC1 can stably lysogenize its host, it possesses some desirable characteristics for use in phage therapy. Phage JC1 has a broad host range and requires the inner core of the bacterial LPS for infection. Bacteria that mutate to evade infection by JC1 may develop a fitness disadvantage as seen in previously characterized LPS mutants lacking inner core.
JC1 噬菌体是一种 C1 形态的噬菌体，从宿主菌株 Van1 中分离得到。该噬菌体能够感染广泛的复杂（Bcc）物种。JC1 基因组与 Bcep22 样噬菌体和许多其他噬菌体表现出显著的相似性和同线性。JC1 基因组的大小为 61182bp，G+C 含量为 65.4%，预测编码 76 种蛋白质和 1 个 tRNA 基因。与其他噬菌体不同，JC1 在其复制模块中编码一个假定的解旋酶基因，其组织形式在以前分析的噬菌体中未发现。JC1 基因组还包含 3 个有趣的 moron 基因，它们编码一个碳储存调节剂（CsrA）、一个 N-乙酰基转移酶和一个磷酸腺苷磷酸硫酸盐（PAPS）还原酶。JC1 可以稳定地溶原化其宿主 Van1 并整合到基因的 5'端。这是首次报道 Bcep22 样噬菌体的稳定整合。与在 30°C 相比，JC1 在 37°C 时具有更高的全局毒性指数（分别为 0.8 和 0.21）；然而，感染效率和溶原稳定性不受温度变化的影响，在裂解和溶原生活方式之间似乎不存在可观察到的温度敏感开关。尽管 JC1 可以稳定地溶原化其宿主，但它具有一些在噬菌体治疗中使用的理想特性。JC1 噬菌体具有广泛的宿主范围，并且需要细菌 LPS 的内核心才能感染。细菌如果发生突变以逃避 JC1 的感染，可能会像以前表征的缺乏内核心的 LPS 突变体一样，出现适应性劣势。
