Sugimoto I, Hiramatsu S, Murakami D, Fujie M, Usami S, Yamada T
Department of Molecular Biotechnology, Graduate School of ADSM, Hiroshima University, 1-4-1 Kagamiyama, Hiroshima, Higashi, 739-8527, Japan.
Virology. 2000 Nov 10;277(1):119-26. doi: 10.1006/viro.2000.0590.
Using a halo assay with E. coli lysates expressing Chlorella virus CVK2 genes on a cosmid contig, two different algal-lytic activities against Chlorella strain NC64A cells were found to be encoded on the CVK2 genome. The gene for vAL-1, one of the two activities, encoded a 349-aa ORF, which was homologous to PBCV-1 A215L and CVN1 CL-2. The vAL-1 gene was expressed at relatively early stages of the virus life cycle; transcripts and translation products appeared at 60 and 90 min postinfection, respectively. The vAL-1 protein was not incorporated into the viral particles but remained in the cell lysate, suggesting a role in the digestion of the cell wall before viral release at the final stage of infection. Cell wall materials isolated from Chlorella strain NC64A cells were digested by vAL-1 and degradation products were detected on TLC. In addition to Chlorella strain NC64A, vAL-1 lysed cells of four C. vulgaris strains as well as Chlorella sp. SAG-241-80.
利用一种噬菌斑检测法，在一个黏粒重叠群上用表达小球藻病毒CVK2基因的大肠杆菌裂解物进行检测，发现针对小球藻NC64A菌株细胞的两种不同的溶藻活性由CVK2基因组编码。这两种活性之一的vAL-1基因编码一个349个氨基酸的开放阅读框，它与PBCV-1 A215L和CVN1 CL-2同源。vAL-1基因在病毒生命周期的相对早期阶段表达；转录本和翻译产物分别在感染后60分钟和90分钟出现。vAL-1蛋白没有被整合到病毒颗粒中，而是留在细胞裂解物中，这表明它在感染末期病毒释放之前对细胞壁的消化过程中发挥作用。从小球藻NC64A菌株细胞中分离出的细胞壁物质被vAL-1消化，并在薄层层析上检测到降解产物。除了小球藻NC64A菌株外，vAL-1还能裂解四种普通小球藻菌株以及小球藻SAG-241-80的细胞。
