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Full-Text Articles in Life Sciences
A Functional K+ Channel From Tetraselmis Virus 1, A Member Of The Mimiviridae, Kerri Kukovetz, Brigitte Hertel, Christopher R. Schvarcz, Andrea Saponaro, Mirja Manthey, Ulrike Burk, Timo Greiner, Grieg F. Steward, James L. Van Etten, Anna Moroni, Gerhard Thiel, Oliver Rauh
A Functional K+ Channel From Tetraselmis Virus 1, A Member Of The Mimiviridae, Kerri Kukovetz, Brigitte Hertel, Christopher R. Schvarcz, Andrea Saponaro, Mirja Manthey, Ulrike Burk, Timo Greiner, Grieg F. Steward, James L. Van Etten, Anna Moroni, Gerhard Thiel, Oliver Rauh
Nebraska Center for Virology: Faculty Publications
Potassium ion (K+) channels have been observed in diverse viruses that infect eukaryotic marine and freshwater algae. However, experimental evidence for functional K+ channels among these alga-infecting viruses has thus far been restricted to members of the family Phycodnaviridae, which are large, double-stranded DNA viruses within the phylum Nucleocytoviricota. Recent sequencing projects revealed that alga-infecting members of Mimiviridae, another family within this phylum, may also contain genes encoding K+ channels. Here we examine the structural features and the functional properties of putative K+ channels from four cultivated members of Mimiviridae. While all four proteins contain variations …
Dynamic Attachment Of Chlorovirus Pbcv-1 To Chlorella Variabilis, Irina Agarkova, Brigitte Hertel, Xinzheng Zhang, Les Lane, Alexander Tchourbanov, David D. Dunigan, Gerhard Thiel, Michael G. Rossmann, James L. Van Etten
Dynamic Attachment Of Chlorovirus Pbcv-1 To Chlorella Variabilis, Irina Agarkova, Brigitte Hertel, Xinzheng Zhang, Les Lane, Alexander Tchourbanov, David D. Dunigan, Gerhard Thiel, Michael G. Rossmann, James L. Van Etten
Nebraska Center for Virology: Faculty Publications
Chloroviruses infect their hosts by specifically binding to and degrading the cell wall of their algal hosts at the site of attachment, using an intrinsic digesting enzyme(s). Chlorovirus PBCV-1 stored as a lysate survived longer than virus alone, suggesting virus attachment to cellular debris may be reversible. Ghost cells (algal cells extracted with methanol) were used as a model to study reversibility of PBCV-1 attachment because ghost cells are as susceptible to attachment and wall digestion as are live cells. Reversibility of attachment to ghost cells was examined by releasing attached virions with a cell wall degrading enzyme extract. The …
Evaluation Of Higher Plant Virus Resistance Genes In The Green Alga, Chlorella Variabilis Nc64a, During The Early Phase Of Infection With Paramecium Bursaria Chlorella Virus-1, Janet M. Rowe, David D. Dunigan, Guillaume Blanc, James R. Gurnon, Yuannan Xia, James L. Van Etten
Evaluation Of Higher Plant Virus Resistance Genes In The Green Alga, Chlorella Variabilis Nc64a, During The Early Phase Of Infection With Paramecium Bursaria Chlorella Virus-1, Janet M. Rowe, David D. Dunigan, Guillaume Blanc, James R. Gurnon, Yuannan Xia, James L. Van Etten
Nebraska Center for Virology: Faculty Publications
With growing industrial interest in algae plus their critical roles in aquatic systems, the need to understand the effects of algal pathogens is increasing. We examined a model algal host–virus system, Chlorella variabilis NC64A and virus, PBCV-1. C. variabilis encodes 375 homologs to genes involved in RNA silencing and in response to virus infection in higher plants. Illumina RNA-Seq data showed that 325 of these homologs were expressed in healthy and early PBCV-1 infected (≤60 min) cells. For each of the RNA silencing genes to which homologs were found, mRNA transcripts were detected in healthy and infected cells. C. variabilis …
Paramecium Bursaria Chlorella Virus 1 Proteome Reveals Novel Architectural And Regulatory Features Of A Giant Virus, David Dunigan, Ronald Cerny, Andrew T. Bauman, Jared C. Roach, Leslie C. Lane, Irina V. Agarkova, Kurt William Wulser, Giane M. Yanai-Balser, James R. Gurnon, Jason C. Vitek, Bernard J. Kronschnabel, Adrien Jeannard, Guillaume Blanc, Chris Upton, Garry Duncan, O. William Mcclung, Fangrui Ma, James L. Van Etten
Paramecium Bursaria Chlorella Virus 1 Proteome Reveals Novel Architectural And Regulatory Features Of A Giant Virus, David Dunigan, Ronald Cerny, Andrew T. Bauman, Jared C. Roach, Leslie C. Lane, Irina V. Agarkova, Kurt William Wulser, Giane M. Yanai-Balser, James R. Gurnon, Jason C. Vitek, Bernard J. Kronschnabel, Adrien Jeannard, Guillaume Blanc, Chris Upton, Garry Duncan, O. William Mcclung, Fangrui Ma, James L. Van Etten
Nebraska Center for Virology: Faculty Publications
The 331 kilobase pairs chlorovirus PBCV-1 genome was re-sequenced and annotated to correct errors in the original 15 year old sequence; forty codons was considered the minimum protein size of an open reading frame. PBCV-1 encodes 416 predicted protein encoding sequences and 11 tRNAs. A proteome analysis was also conducted on highly purified PBCV-1 virions using two mass-spectrometry based protocols. The mass spectrometry-derived data were compared to PBCV-1 and its host Chlorella variabilis NC64A predicted proteomes. Combined, these analyses revealed 148 unique virus-encoded proteins associated with the virion (about 35% of the coding capacity of the virus) and one host …
Characterization Of A Monothiol Glutaredoxin Encoded By Chlorella Virus Pbcv-1, Lisa A. Fitzgerald, Yuanzheng Zhang, Gentry L. Lewis, James L. Van Etten
Characterization Of A Monothiol Glutaredoxin Encoded By Chlorella Virus Pbcv-1, Lisa A. Fitzgerald, Yuanzheng Zhang, Gentry L. Lewis, James L. Van Etten
Nebraska Center for Virology: Faculty Publications
Annotation of the 330-kb Chlorella virus PBCV-1 genome identified a 237 nucleotide gene (a438l) that codes for a protein with ~35% amino acid identity to glutaredoxins (Grx) found in other organisms. The PBCV-1 protein resembles classical Grxs in both size (9 kDa) and location of the active site (N-terminus). However, the PBCV-1 Grx is unusual because it contains a monothiol active site (CPYS) rather than the typical dithiol active site (CPYC). To examine this unique active site, four sitespecific mutants (CPYC, CPYA, SPYC, and SPYS) were constructed to determine if the N-terminal cysteine is necessary for enzyme activity. …
Sequence And Annotation Of The 314-Kb Mt325 And The 321-Kb Fr483 Viruses That Infect Chlorella Pbi, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, Tamara Feldblyum, James Hartigan, James L. Van Etten
Sequence And Annotation Of The 314-Kb Mt325 And The 321-Kb Fr483 Viruses That Infect Chlorella Pbi, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, Tamara Feldblyum, James Hartigan, James L. Van Etten
Nebraska Center for Virology: Faculty Publications
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 …
Sequence And Annotation Of The 369-Kb Ny-2a And The 345-Kb Ar158 Viruses That Infect Chlorella Nc64a, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, Tamara Feldblyum, Willaim C. Nierman, James L. Van Etten
Sequence And Annotation Of The 369-Kb Ny-2a And The 345-Kb Ar158 Viruses That Infect Chlorella Nc64a, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, Tamara Feldblyum, Willaim C. Nierman, James L. Van Etten
Nebraska Center for Virology: Faculty Publications
Viruses NY-2A and AR158, members of the family Phycodnaviridae, genus Chlorovirus, infect the fresh water, unicellular, eukaryotic, chlorella-like green alga, Chlorella NC64A. The 368,683-bp genome of NY-2A and the 344,690-bp genome of AR158 are the two largest chlorella virus genomes sequenced to date; NY-2A contains 404 putative protein-encoding and 7 tRNA-encoding genes and AR158 contains 360 putative protein-encoding and 6 tRNA-encoding genes. The protein-encoding genes are almost evenly distributed on both strands, and intergenic space is minimal. Two of the NY-2A genes encode inteins, the large subunit of ribonucleotide reductase and a superfamily II helicase. These are the …
Ornithine Decarboxylase Encoded By Chlorella Virus Pbcv-1, Tiara A. Morehead, James R. Gurnon, Byron Adams, Kenneth Nickerson, Lisa A. Fitzgerald, James L. Van Etten
Ornithine Decarboxylase Encoded By Chlorella Virus Pbcv-1, Tiara A. Morehead, James R. Gurnon, Byron Adams, Kenneth Nickerson, Lisa A. Fitzgerald, James L. Van Etten
Nebraska Center for Virology: Faculty Publications
Sequence analysis of the 330-kb genome of chlorella virus PBCV-1 revealed an open reading frame, A207R, which encodes a protein with 37–41% amino acid identity to ornithine decarboxylase (ODC) from many eukaryotic organisms. The a207r gene was cloned and the protein was expressed as a His-A207R fusion protein in Escherichia coli. The recombinant protein catalyzes pyridoxal 5’-phosphate-dependent decarboxylation of ornithine to putrescine, the first step in the polyamine biosynthetic pathway The enzyme has a pH optimum of 9.0 and a temperature optimum of 42°C, and it requires dithiothreitol for maximal activity. The enzyme has a Km, for ornithine of …
Chlorella Virus Pbcv-1 Encodes A Functional Homospermidine Synthase, Annette Kaiser, Michael Vollmert, Dorothea Tholl, Michael V. Graves, James Gurnon, Weimei Xing, Amber D. Lisec, Kenneth Nickerson, James L. Van Etten
Chlorella Virus Pbcv-1 Encodes A Functional Homospermidine Synthase, Annette Kaiser, Michael Vollmert, Dorothea Tholl, Michael V. Graves, James Gurnon, Weimei Xing, Amber D. Lisec, Kenneth Nickerson, James L. Van Etten
Kenneth Nickerson Papers
Sequence analysis of the 330-kb genome of chlorella virus Paramecium bursaria chlorella virus 1 (PBCV-1) revealed an open reading frame, A237R, that encodes a protein with 34% amino acid identity to homospermidine synthase from Rhodopseudomonas viridis. Expression of the a237r gene product in Escherichia coli established that the recombinant enzyme catalyzes the NAD+-dependent formation of homospermidine from two molecules of putrescine. The a237r gene is expressed late in PBCV-1 infection. Both uninfected and PBCV-1-infected chlorella, as well as PBCV-1 virions, contain homospermidine, along with the more common polyamines putrescine, spermidine, and cadaverine. The total number of polyamine …