Isolation and characterization of Chlorella viruses from freshwater sources in Korea.
We isolated 23 Chlorella viruses from 9 Korean cities. The viruses were initially amplified in the Chlorella strain NC64A. Pure isolates were obtained by repeated plaque isolations. A SDS-PAGE analysis revealed similar but distinct protein patterns, both among the group of purified viruses and in comparison with the prototype Chlorella virus PBCV-1. Digestions of the 330- to 350-kb genomic DNAs with 10 restriction enzymes revealed different restriction fragment patterns among the isolates. One isolate, SS-1, was resistant to digestion with HindIII, PvuII, AluI, and HaeIII, indicating methylation at the AGCT or GC sequences. Some isolates reacted with antiserum against PBCV-1. The others that did not react to this PBCV-1 antibody reacted to the antibody that was raised against purified HS-2 virion. The tRNA-coding regions of 8 Chlorella viruses were cloned and sequenced. These viruses contained 14-16 tRNA genes within a 1.2- to 2-kb region, except for the SS-1 isolate, which had a 1039-bp spacer in a cluster of 11 tRNA genes. The SS-1 spacer contained an open-reading frame (ORF) of 294 amino acids. This ORF had a 51% amino acid sequence similarity to the PBCV-1 ORF A478L. A Southern blot analysis suggested that it was a novel gene that lacked a homologue in PBCV-1.
Cho
Hyun-Hwa
HH
Department of Microbiology Pukyong National University, Busan, Korea. choitj@pknu.ac.kr
Park
Hyoun-Hyang
HH
Kim
Jong-Oh
JO
Choi
Tae-Jin
TJ
D000595:Amino Acid Sequence; D015139:Blotting, Southern; D015153:Blotting, Western; D036022:Capsid Proteins / Q000737:chemistry; D002708:Chlorella / Q000648:ultrastructure / Q000821:virology*; D004591:Electrophoresis, Polyacrylamide Gel; D007723:Korea; D008969:Molecular Sequence Data; D005810:Multigene Family; D010942:Plant Viruses / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology / Q000648:ultrastructure; D012343:RNA, Transfer / Q000235:genetics; D014871:Water Microbiology
D036022:Capsid Proteins; D012343:RNA, Transfer