DNA methyltransferases and DNA site-specific endonucleases encoded by chlorella viruses

Abstract

Large polyhedral (diameter of 150 to 190 nm) dsDNA-containing ( > 300 kbp) viruses which infect certain unicellular, eukaryotic, chlorella-like green algae are common in fresh water collected throughout the world (Van Etten et al., 1985; Schuster et al., 1986; Zhang et al., 1988; Reisser et al., 1988; Yamada et al., 1991). The hosts for these lytic chlorella viruses are exsymbiotic Chlorella strains NC64A and Pbi, originally isolated from the protozoan Paramecium bursaria. Chlorella viruses, which can be produced in large quantities, are the first viruses infecting a photosynthetic eukaryotic organism which can be plaque assayed (Van Etten et al., 1983) and have been given family status with the name Phycodnaviridae (Francki et al., 1991). A comprehensive review on the chlorella viruses has recently been published (Van Etten et al., 1991).KeywordsThymidylate SynthetaseParamecium BursariaChlorella VirusCytosine MethyltransferasesNeisseria LactamicaThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.