Zimmerly, StevenSoufi, Bahar2019-05-282019-05-282019-05-15Soufi, B. (2019). AbiK: A Novel Polymerase That Confers Resistance to Phage Infection (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.http://hdl.handle.net/1880/110439The abortive infection K (AbiK) system of Lactococcus lactis is a powerful antiviral defense mechanism that acts in the period after phage DNA enters the cell but before new progeny are released. The N-terminal domain of AbiK encodes a novel DNA polymerase that in vitro uses an internal amino acid to synthesize an un-templated DNA. The C-terminal domain of AbiK, on the other hand, has not been biochemically characterized. In the first of two projects presented in this thesis, strategies were devised to identify the amino acid priming site in AbiK. A close examination of data has narrowed down the priming site to two highly-conserved tyrosines in the N-terminal sequence of AbiK. In the second project, the characterization of the AbiK’s C terminal domain was undertaken to identify its function. This study uncovers a novel RNA modification activity, and provides evidence that AbiK’s C-terminal domain has ribonuclease activity.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Biochemistrymaster thesis10.11575/PRISM/36599