The mechanism of DNA packaging for double-stranded DNA viruses will be studied in the Bacillus subtilis bacteriophage ?29, the most efficient in vitro viral packaging system known. Using an integrated genetic, biochemical and structural approach, we will characterize protein conformational change and movement in the transiently assembled packaging motor during DNA encapsidation. The mechanism of packaging in ?29 will serve as a model for animal virus packaging in the analogous herpesvirus and adenovirus systems, and aid in the search for new antiviral therapies. Due to similarities between the ?29 ATPase and other ring translocases, insights gained from the study of ?29 packaging will also provide insight into the basic principles of macromolecular motor function in higher organisms. To elucidate the mechanism of DNA packaging: an atomic structure of the ?29 DNA packaging motor will be obtained by fitting of X-ray crystallographic structures of motor components into high-resolution cryoEM maps of the motor complex (Aim 1);high-resolution cryoEM reconstruction of packaging intermediates will identify mobile elements during DNA packaging (Aim 2);and mutagenesis and biochemical analysis will dissect functional residues in the ATPase and connector that are crucial for motor function, including coordination and communication, during DNA packaging (Aim 3).

Public Health Relevance

The assembly and movement of macromolecules in biological systems drive all aspects of health and disease at the cellular level. Study of the structure, assembly and function of the bacterial virus X29 DNA packaging motor serves as a model for understanding these fundamental biological principles and can inform us about similar processes in higher organisms. The DNA packaging process of X29 will also serve as a model for understanding similar events in the medically relevant herpesviruses and adenoviruses, thus providing targets for the development of new antiviral therapies.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM095516-04
Application #
8726431
Study Section
Prokaryotic Cell and Molecular Biology Study Section (PCMB)
Program Officer
Sakalian, Michael
Project Start
2011-09-30
Project End
2015-08-31
Budget Start
2014-09-01
Budget End
2015-08-31
Support Year
4
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Dentistry
Type
Schools of Dentistry/Oral Hygn
DUNS #
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Morais, Marc C (2016) Breaking the symmetry of a viral capsid. Proc Natl Acad Sci U S A 113:11390-11392
Jardine, Paul J (2016) Packaging Models versus Modeling Packaging. Biophys J 110:287-288
Mao, Huzhang; Saha, Mitul; Reyes-Aldrete, Emilio et al. (2016) Structural and Molecular Basis for Coordination in a Viral DNA Packaging Motor. Cell Rep 14:2017-2029
Zhao, Wei; Jardine, Paul J; Grimes, Shelley (2015) An RNA Domain Imparts Specificity and Selectivity to a Viral DNA Packaging Motor. J Virol 89:12457-66
Cao, Sheng; Saha, Mitul; Zhao, Wei et al. (2014) Insights into the structure and assembly of the bacteriophage 29 double-stranded DNA packaging motor. J Virol 88:3986-96
Choi, Kyung H; Morais, Marc (2014) Use of small-angle X-ray scattering to investigate the structure and function of dengue virus NS3 and NS5. Methods Mol Biol 1138:241-52
Saha, Mitul; Morais, Marc C (2012) FOLD-EM: automated fold recognition in medium- and low-resolution (4-15 A) electron density maps. Bioinformatics 28:3265-73
Zhao, Wei; Saha, Mitul; Ke, Ailong et al. (2012) A three-helix junction is the interface between two functional domains of prohead RNA in 29 DNA packaging. J Virol 86:11625-32
Harjes, Elena; Kitamura, Aya; Zhao, Wei et al. (2012) Structure of the RNA claw of the DNA packaging motor of bacteriophage ýý29. Nucleic Acids Res 40:9953-63