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Articles 61 - 69 of 69

Full-Text Articles in Viruses

Sequence And Annotation Of The 288-Kb Atcv-1 Virus That Infects An Endosymbiotic Chlorella Strain Of The Heliozoon Acanthocystis Turfacea, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, James Hartigan, Artur J.P. Pfitzner, Ella Hoffart, James L. Van Etten Jan 2007

Sequence And Annotation Of The 288-Kb Atcv-1 Virus That Infects An Endosymbiotic Chlorella Strain Of The Heliozoon Acanthocystis Turfacea, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, James Hartigan, Artur J.P. Pfitzner, Ella Hoffart, James L. Van Etten

James Van Etten Publications

Acanthocystis turfacea chlorella virus (ATCV-1), a prospective member of the family Phycodnaviridae, genus Chlorovirus, infects a unicellular, eukaryotic, chlorella-like green alga, Chlorella SAG 3.83, that is a symbiont in the heliozoon A. turfacea. The 288,047-bp ATCV-1 genome is the first virus to be sequenced that infects Chlorella SAG 3.83. ATCV-1 contains 329 putative protein-encoding and 11 tRNA-encoding genes. The protein-encoding genes are almost evenly distributed on both strands and intergenic space is minimal. Thirty-four percent of the viral gene products resemble entries in the public databases, including some that are unexpected for a virus. For example, these …


Chlorella Viruses Contain Genes Encoding A Complete Polyamine Biosynthetic Pathway, Sascha Baumann, Adrienne Sander, James Gurnon, Giane M. Yanai-Balser, James L. Van Etten, Markus Piotrowski Jan 2007

Chlorella Viruses Contain Genes Encoding A Complete Polyamine Biosynthetic Pathway, Sascha Baumann, Adrienne Sander, James Gurnon, Giane M. Yanai-Balser, James L. Van Etten, Markus Piotrowski

James Van Etten Publications

Two genes encoding the putative polyamine biosynthetic enzymes agmatine iminohydrolase (AIH) and N-carbamoylputrescine amidohydrolase (CPA) were cloned from the chloroviruses PBCV-1, NY-2A and MT325. They were expressed in Escherichia coli to form C-terminal (His)6-tagged proteins and the recombinant proteins were purified by Ni2+- binding affinity chromatography. The biochemical properties of the two enzymes are similar to AIH and CPA enzymes from Arabidopsis thaliana and Pseudomonas aeruginosa. Together with the previously known virus genes encoding ornithine/arginine decarboxlyase (ODC/ADC) and homospermidine synthase, the chloroviruses have genes that encode a complete set of functional enzymes that synthesize the rare polyamine homospermidine from arginine …


Chlorella Virus Mt325 Encodes Water And Potassium Channels That Interact Synergistically, Sabrina Gazzarrini, Ming Kang, Svetlana Epimashko, James L. Van Etten, Jack Dainty, Gerhard Thiel, Anna Moroni Feb 2006

Chlorella Virus Mt325 Encodes Water And Potassium Channels That Interact Synergistically, Sabrina Gazzarrini, Ming Kang, Svetlana Epimashko, James L. Van Etten, Jack Dainty, Gerhard Thiel, Anna Moroni

James Van Etten Publications

Fast and selective transport of water through cell membranes is facilitated by water channels. Water channels belonging to the major intrinsic proteins (MIPs) family have been found in all three domains of life, Archaea, Bacteria, and Eukarya. Here we show that Chlorella virus MT325 has a water channel gene, aqpv1, that forms a functional aquaglyceroporin in oocytes. aqpv1 is transcribed during infection together with MT325 kcv, a gene encoding a previously undescribed type of viral potassium channel. Coexpression of AQPV1 and MT325-Kcv in Xenopus oocytes synergistically increases water transport, suggesting a possible concerted action of the two channels in …


Chlorella Viruses, Takashi Yamada, Hideki Onimatsu, James L. Van Etten Jan 2006

Chlorella Viruses, Takashi Yamada, Hideki Onimatsu, James L. Van Etten

James Van Etten Publications

Chlorella viruses or chloroviruses are large, icosahedral, plaque‐forming, double‐stranded‐DNA— containing viruses that replicate in certain strains of the unicellular green alga Chlorella. DNA sequence analysis of the 330‐kbp genome of Paramecium bursaria chlorella virus 1 (PBCV‐1), the prototype of this virus family (Phycodnaviridae), predict ∼366 protein‐encoding genes and 11 tRNA genes. The predicted gene products of ∼50% of these genes resemble proteins of known function, including many that are completely unexpected for a virus. In addition, the chlorella viruses have several features and encode many gene products that distinguish them from most viruses. These products include: (1) multiple …


The Structure Of A T=169d Algal Virus, Pbcv-1, At 15Å Resolution, X. Yan, V. Bowman, N. H. Olson, James Gurnon, James L. Van Etten, Michael G. Rossmann, T. S. Baker Jan 2005

The Structure Of A T=169d Algal Virus, Pbcv-1, At 15Å Resolution, X. Yan, V. Bowman, N. H. Olson, James Gurnon, James L. Van Etten, Michael G. Rossmann, T. S. Baker

James Van Etten Publications

Paramecium bursaria chlorella virus 1 (PBCV-1) (genus Chlorovirus, family Phycodnaviridae), infects certain unicellular, exsymbiotic, chlorella-like green algae [1]. The PBCV-1 virion (~1x109 Da) has a linear dsDNA genome (330kbp) and contains at least 100 different proteins [1, unpublished data]. A published cryo-electron microscopy and three-dimensional (3D) image reconstruction of PBCV-1 (26Å resolution) revealed that the outer icosahedral glycoprotein capsid, with a maximum diameter of 1,900Å along the five-fold axis, consists of 1680 trimeric capsomers (trimer) and 12 pentameric capsomers (pentamer) [2]. These capsomers are arranged on a T=169d (h=7, k=8) quasi-equivalent lattice. The trimers and pentamers are organized into 20 …


Functional Implication Of The Trna Genes Encoded In The Chlorella Virus Pbcv-L Genome, Da Young Lee, Michael V. Graves, James L. Van Etten, Tae-Jin Choi Jan 2005

Functional Implication Of The Trna Genes Encoded In The Chlorella Virus Pbcv-L Genome, Da Young Lee, Michael V. Graves, James L. Van Etten, Tae-Jin Choi

James Van Etten Publications

The prototype Chlorella virus PBCV-l encodes 11 tRNA genes and over 350 protein-encoding genes in its 330 kbp genome. Initial attempts to overexpress the recombinant A189/192R protein, a putative virus attachment protein, in E. coli strain BL21(DE3) SI were unsuccessful, and multiple protein bands were detected on Western blots. However, the full-length A189/192R recombinant protein or fragments derived from it were detected when they were expressed in E. coli BL21 CodonPlus (DE3) RIL, which contains extra tRNAs. Codon usage analysis of the a1891192r gene showed highly biased usage of the AGA and AUA codons compared to genes encoded by E. …


Glycosyltransferases Encoded By Viruses, Nicolas Markine-Goriaynoff, Laurent Gillet, James L. Van Etten, Haralambos Korres, Naresh Verma, Alain Vanderplasschen Jan 2004

Glycosyltransferases Encoded By Viruses, Nicolas Markine-Goriaynoff, Laurent Gillet, James L. Van Etten, Haralambos Korres, Naresh Verma, Alain Vanderplasschen

James Van Etten Publications

Studies of cellular biology in recent decades have highlighted the crucial roles of glycans in numerous important biological processes, raising the concept of glycomics that is now considered as important as genomics, transcriptomics and proteomics. For millions of years, viruses have been co-evolving with their hosts. Consequently, during this co-evolution process, viruses have acquired mechanisms to mimic, hijack or sabotage host processes that favour their replication, including mechanisms to modify the glycome. The importance of the glycome in the regulation of host–virus interactions has recently led to a new concept called ‘glycovirology’. One fascinating aspect of glycovirology is the study …


Can Large Dsdna-Containing Viruses Provide Information About The Minimal Genome Size Required To Support Life?, James L. Van Etten Jan 1999

Can Large Dsdna-Containing Viruses Provide Information About The Minimal Genome Size Required To Support Life?, James L. Van Etten

James Van Etten Publications

The genomes of a few viruses, such as Bacillus megaterium phage G (670 kb) and the chlorella viruses (330 to 380 kb), are larger than the predicted minimal genome size required to support life (ca. 320 kb). A comparison of the 256 proteins predicted to be required for life with the putative 376 proteins encoded by chlorella virus PBCV-1, as well as those encoded by other large viruses, indicates that viruses lack many of these “essential” genes. Consequently, it is unlikely that viruses will aid in determining the minimal number and types of genes required for life. However, viruses may …


Experimentation To Develop Procedures To Be Used In The Investigation Of The Effects Of Restriction On The Unmodified Dna Of The Bacteriophage Lamda, John Haynes Jun 1973

Experimentation To Develop Procedures To Be Used In The Investigation Of The Effects Of Restriction On The Unmodified Dna Of The Bacteriophage Lamda, John Haynes

Honors Theses

The results of experimentation approximately twenty years ago with variuos bacteriophages by Ralston and Krueger16, Anderson and Felix1, Luria and Human12, and by Bertani and Weigle2 have shown that the host range of a given phage depends directly on the bacterial strain on which the phage has last propagated. This event came to be known as host-induced modification or host-controlled variation. As this phage host range is controlled by the host environment and can be altered from one generation to another it has, according to Luria, made microbiology "the last stronghold of Lamarckism" …