title: Analysis of 74 kb of DNA located at the right end of the 330-kb chlorella virus PBCV-1 genome.
abstract: This report completes a preliminary analysis of the sequence of the 330,740-bp chlorella virus PBCV-1 genome, the largest virus genome to be sequenced to date. The PBCV-1 genome is 57% the size of the genome from the smallest self-replicating organism, Mycoplasma genitalium. Analysis of 74 kb of newly sequenced DNA, from the right terminus of the PBCV-1 genome, revealed 153 open reading frames (ORFs) of 65 codons or longer. Eighty-five of these ORFs, which are evenly distributed on both strands of the DNA, were considered major ORFs. Fifty-nine of the major ORFs were separated by less than 100 bp. The largest intergenic distance was 729 bp, which occurred between two ORFs located in the 2.2-kb inverted terminal repeat region of the PBCV-1 genome. Twenty-seven of the 85 major ORFs resemble proteins in databases, including the large subunit of ribonucleotide diphosphate reductase, ATP-dependent DNA ligase, type II DNA topoisomerase, a helicase, histidine decarboxylase, dCMP deaminase, dUTP pyrophosphatase, proliferating cell nuclear antigen, a transposase, fungal translation elongation factor 3 (EF-3), UDP glucose dehydrogenase, a protein kinase, and an adenine DNA methyltransferase and its corresponding DNA site-specific endonuclease. Seventeen of the 153 ORFs resembled other PBCV-1 ORFs, suggesting that they represent either gene duplications or gene families.
authors.affiliation: Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68583-0722, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: Z
authors.initials: Z
authors.lastname: Lu
authors.forename: L
authors.initials: L
authors.lastname: Sun
authors.forename: S
authors.initials: S
authors.lastname: Ropp
authors.forename: G F
authors.initials: GF
authors.lastname: Kutish
authors.forename: D L
authors.initials: DL
authors.lastname: Rock
authors.forename: J L
authors.initials: JL
authors.lastname: Van Etten
mesh_terms: D002708:Chlorella / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis*; D005814:Genes, Viral; D016679:Genome, Viral; D008969:Molecular Sequence Data; D017862:Phycodnaviridae / Q000235:genetics*
chemical_list: D004279:DNA, Viral