Craig PetersonBaier, Alexander S2023-08-282023-08-282023-06-2810.13028/g1wk-ja53https://hdl.handle.net/20.500.14038/52455Chromatin refers to the higher-order organization of DNA in the nucleus of the cell, and this architecture fundamentally underpins essential cellular processes such as response to environmental change, differentiation of cell type, and more as well as enables the incredible information density of nuclear DNA contents. At its simplest, chromatin consists of approximately 147 base pairs of DNA wrapped around an octamer of histones, termed the nucleosome. Cells further discern between nucleosomes via means such as highly regulated spacing along genes, inter-nucleosome positioning, post-translational histone modifications, or histone variations, all of which are regulated by a class of nuclear enzymes called chromatin remodeling enzymes. My thesis focuses on the S. cerevisiae chromatin remodeling enzyme SWR1C, which exchanges canonical histone H2A for variant H2A.Z. This histone variant is enriched proximal to important sites such as actively transcribed genes, centromeres, and double strand DNA breaks. Prior in vitro characterization of SWR1C has been limited by the inability to produce complex nucleosomal substrates. My research reports the first use of asymmetrically assembled nucleosomes to probe the activity of SWR1C. Herein I deliver concrete confirmation of SWR1C preference for linker distal H2A eviction and novel insights regarding the dual essentiality of the nucleosomal acidic patch for SWR1C activity, as well as stimulation of activity by the contralateral H2A.Z dimer and linker DNA. This work brings forth new insights into the behavior, structure, and function of SWR1C and reveals its unique features as compared to other closely related chromatin remodeling enzymes.en-USCopyright © 2023 Alexander S. BaierAll Rights ReservedChromatinSWR1CH2A.ZNucleosome acidic patchDoctoral Dissertation0000-0003-1647-9477