SEQUENCE AND ANNOTATION OF THE 314-KB MT325 AND THE 321-KB FR483 VIRUSES THAT INFECT CHLORELLA Pbi Lisa A. Fitzgerald 1 , Michael V. Graves 2 , Xiao Li 2 , Tamara Feldblyum 3 , James Hartigan 4 , and James L. Van Etten 5,* 1Deparment of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304 2Department of Biological Sciences, University of Massachusetts-Lowell, Lowell, MA 01854 3The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, MD 20850 4Agencourt Bioscience Corporation, 500 Cummings Center, Suite 2450, Beverly, MA 01915 5Deparment of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583-0722 and Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68588-0666 Abstract Viruses MT325 and FR483, members of the family Phycodnaviridae, genus Chlorovirus, infect the fresh water, unicellular, eukaryotic, chlorella-like green alga, Chlorella Pbi. The 314,335-bp genome of MT325 and the 321,240-bp genome of FR483 are the first viruses that infect Chlorella Pbi to have their genomes sequenced and annotated. Furthermore, these genomes are the two smallest chlorella virus genomes sequenced to date, MT325 has 331 putative protein-encoding and 10 tRNA-encoding genes and FR483 has 335 putative protein-encoding and 9 tRNA-encoding genes. The protein- encoding genes are almost evenly distributed on both strands, and intergenic space is minimal. Approximately 40% of the viral gene products resemble entries in public databases, including some that are the first of their kind to be detected in a virus. For example, these unique gene products include an aquaglyceroporin in MT325, a potassium ion transporter protein and an alkyl sulfatase in FR483, and a dTDP-glucose pyrophosphorylase in both viruses. Comparison of MT325 and FR483 protein-encoding genes with the prototype chlorella virus PBCV-1 indicate that approximately 82% of the genes are present in all three viruses. Keywords Chlorella viruses; Phycodnaviridae; virus MT325; virus FR483; genome sequence INTRODUCTION Members and prospective members of the family Phycodnaviridae consist of a genetically diverse, but morphologically similar, group of large dsDNA-containing viruses (170–560 kb) that infect eukaryotic algae from both fresh and marine waters (Kang et al., 2005;Wilson et al., 2005b). The phycodnaviruses are among the virioplankton recognized as important ecological elements in aqueous environments (Suttle, 2005). They, along with other viruses, *Corresponding author. Mailing address: Department of Plant Pathology, University of Nebraska-Lincoln, NE 68383-0722. Phone: (402) 472-3168. Fax: (402) 472-2853. E-mail: jvanetten@unlnotes.unl.edu Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author Manuscript Virology. Author manuscript; available in PMC 2008 February 20. Published in final edited form as: Virology. 2007 February 20; 358(2): 459–471. NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript