Discovery and engineering of antiviral defense systems in bacteria and archaea

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, September, 2020

Bibliographic Details
Main Author: Gao, Linyi,Ph. D.Massachusetts Institute of Technology.
Other Authors: Feng Zhang.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2021
Subjects:
Online Access:https://hdl.handle.net/1721.1/130594
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author Gao, Linyi,Ph. D.Massachusetts Institute of Technology.
author2 Feng Zhang.
author_facet Feng Zhang.
Gao, Linyi,Ph. D.Massachusetts Institute of Technology.
author_sort Gao, Linyi,Ph. D.Massachusetts Institute of Technology.
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description Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, September, 2020
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spelling mit-1721.1/1305942021-05-15T03:17:38Z Discovery and engineering of antiviral defense systems in bacteria and archaea Gao, Linyi,Ph. D.Massachusetts Institute of Technology. Feng Zhang. Massachusetts Institute of Technology. Department of Biological Engineering. Massachusetts Institute of Technology. Department of Biological Engineering Biological Engineering. Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, September, 2020 Cataloged from the official PDF version of thesis. Includes bibliographical references. Viruses are the most abundant and diverse life form on Earth. With over 10³¹ viral particles in existence, viruses fundamentally shape global biogeochemistry and ecology. Most viruses infect bacteria, archaea, and other microbes, and the threat of infection continually challenges microbes' survival. As a consequence of this expansive war, bacteria and archaea have acquired a potent arsenal of molecular defense systems in order to survive. Known defense systems, such as CRISPR, have given rise to transformative technologies including genome editing. However, defense systems as a whole remain underexplored. Continued investigation of these systems and the warfare between microbes and viruses may lead not only to a better understanding of basic microbiology and evolution, but also to new technologies and therapeutic applications. In this thesis, we investigate the collective arsenal of molecular defense systems that bacteria and archaea use to fight viral infections. First, we focus on known defense systems and use protein engineering to increase the specificity and targeting range of CRISPR enzymes for human genome editing. Second, by computational mining and experimental reconstitution, we discover 29 novel defense gene cassettes that are collectively present in one third of all sequenced bacterial and archaeal genomes. These systems incorporate enzymatic activities not previously implicated in antiviral defense, including RNA editing and retron satellite DNA synthesis. In addition, we predict a diverse set of other putative defense genes that remain to be characterized. These results highlight an immense array of molecular functions that bacteria and archaea employ against viruses. by Linyi Gao. Ph. D. Ph.D. Massachusetts Institute of Technology, Department of Biological Engineering 2021-05-14T16:27:06Z 2021-05-14T16:27:06Z 2020 2020 Thesis https://hdl.handle.net/1721.1/130594 1249551561 eng MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided. http://dspace.mit.edu/handle/1721.1/7582 109 pages application/pdf Massachusetts Institute of Technology
spellingShingle Biological Engineering.
Gao, Linyi,Ph. D.Massachusetts Institute of Technology.
Discovery and engineering of antiviral defense systems in bacteria and archaea
title Discovery and engineering of antiviral defense systems in bacteria and archaea
title_full Discovery and engineering of antiviral defense systems in bacteria and archaea
title_fullStr Discovery and engineering of antiviral defense systems in bacteria and archaea
title_full_unstemmed Discovery and engineering of antiviral defense systems in bacteria and archaea
title_short Discovery and engineering of antiviral defense systems in bacteria and archaea
title_sort discovery and engineering of antiviral defense systems in bacteria and archaea
topic Biological Engineering.
url https://hdl.handle.net/1721.1/130594
work_keys_str_mv AT gaolinyiphdmassachusettsinstituteoftechnology discoveryandengineeringofantiviraldefensesystemsinbacteriaandarchaea