Bacteriophage Lambda is an excellent model system for studying virion assembly for the large DNA viruses, including the herpes, pox and adenoviruses. These viruses assemble empty protein shells into which the viral chromosome is packaged. In addition, during DNA packaging of many lambdoid phages and the herpes viruses, long end-to-end polymers of viral DNA are cut at specific sites to generate unit-length molecules.Viral DNA is selected for packaging from a DNA pool that also includes host sequences. This recognition is governed by the interactions of viral packaging proteins with a set of protein binding sites on the viral DNA. How protein-DNA interactions orchestrate packaging is best understood for . We propose to further define these DNA-protein interactions, which have broad implications for virus DNA recognition. We also seek to understand the mechanism of an assembly catalyst that aids recognition steps.While the functioning of the viral DNA packaging enzyme, terminase, has been extensively studied, the role of the shell, especially the shell's portal vertex, has not. We propose experiments on the portal's role in packaging, and seek to define the portal's binding site for terminase. As part of this work we plan to examine the roles of several proteins involved in shell assembly. This work will generate purified packaging proteins and assemblages suitable for structural analysis. Structural information about packaging proteins is crucial for understanding the wealth of genetic information and to assist in design of further studies on the functioning of these proteins.The mechanism of how DNA is translocated into the shell is not understood in any virus system. We propose molecular studies on a series of mutants that have defects in DNA packaging, including DNA translocation. We will also look at the ability of terminase to move DNA, and to pursue a structural analysis of functional domains of terminase.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
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Microbial Physiology and Genetics Subcommittee 2 (MBC)
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Basavappa, Ravi
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University of Iowa
Schools of Medicine
Iowa City
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Feiss, Michael; Young Min, Jea; Sultana, Sawsan et al. (2015) DNA Packaging Specificity of Bacteriophage N15 with an Excursion into the Genetics of a Cohesive End Mismatch. PLoS One 10:e0141934
Rao, Venigalla B; Feiss, Michael (2015) Mechanisms of DNA Packaging by Large Double-Stranded DNA Viruses. Annu Rev Virol 2:351-78
Feiss, Michael; Geyer, Henriette; Klingberg, Franco et al. (2015) Novel DNA packaging recognition in the unusual bacteriophage N15. Virology 482:260-8
Sippy, Jean; Patel, Priyal; Vahanian, Nicole et al. (2015) Genetics of critical contacts and clashes in the DNA packaging specificities of bacteriophages ? and 21. Virology 476:115-123
Feiss, Michael; Rao, Venigalla B (2012) The bacteriophage DNA packaging machine. Adv Exp Med Biol 726:489-509
Giri, Lopamudra; Feiss, Michael G; Bonning, Bryony C et al. (2012) Production of baculovirus defective interfering particles during serial passage is delayed by removing transposon target sites in fp25k. J Gen Virol 93:389-99
Giri, Lopamudra; Li, Huarang; Sandgren, David et al. (2010) Removal of transposon target sites from the Autographa californica multiple nucleopolyhedrovirus fp25k gene delays, but does not prevent, accumulation of the few polyhedra phenotype. J Gen Virol 91:3053-64
Zeng, Lanying; Skinner, Samuel O; Zong, Chenghang et al. (2010) Decision making at a subcellular level determines the outcome of bacteriophage infection. Cell 141:682-91
Feiss, Michael; Reynolds, Erin; Schrock, Morgan et al. (2010) DNA packaging by lambda-like bacteriophages: mutations broadening the packaging specificity of terminase, the lambda-packaging enzyme. Genetics 184:43-52
Tsay, James M; Sippy, Jean; DelToro, Damian et al. (2010) Mutations altering a structurally conserved loop-helix-loop region of a viral packaging motor change DNA translocation velocity and processivity. J Biol Chem 285:24282-9

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