Understanding of chromatin organization and compaction in Archaea is currently limited. The genome of several megabasepairs long is folded by a set of small chromatin proteins to fit into the... Show moreUnderstanding of chromatin organization and compaction in Archaea is currently limited. The genome of several megabasepairs long is folded by a set of small chromatin proteins to fit into the micron-sized cell. A first step in understanding archaeal chromatin organization is to study the action of individual chromatin proteins on DNA. Characterization of the architectural properties of these proteins is essential to understand how they shape and modulate the archaeal genome. This thesis describes the biophysical characterization of several chromatin proteins from the crenarchaeal model organism Sulfolobus solfataricus: Cren7, Sul7, Alba and Sso10a. The architectural properties of these proteins resemble those of their bacterial counterparts, suggesting that they could play a similar role in chromatin organization and global gene regulation. Show less
CRANK is a suite that links different macromolecular X-ray crystallographic programs to solve macromolecular crystal structures automatically from experimental phasing data. In chapter 2, several... Show moreCRANK is a suite that links different macromolecular X-ray crystallographic programs to solve macromolecular crystal structures automatically from experimental phasing data. In chapter 2, several new algorithms implemented within CRANK increase the robustness and speed of the structure solution process. The new MULTICOMB program, discussed in chapter 3, provides a new phase combination algorithm for the density modification step of the structure solution process. MULTICOMB implements a novel advanced multivariate function that considers the single-wavelength anomalous diffraction (SAD) data directly, accounts for the correlation between the initial and density-modified maps and refines errors that can occur in a SAD experiment. Testing of these new algorithms with over 100 real data sets showed a dramatic improvement over state-of-the-art methods. These novel methods were also applied in solving the new structure of the DNA-binding protein Sso10a2 from Sulfolobus solfataricus reported in chapter 4. This structure provides insight to the observed differences in behaviour between Sso10a2 and its close homolog Sso10a. The last chapter of this work describes the crystallization conditions for a recombinant, fully glycosylated form of the human C1 inhibitor protein, which is involved in hereditary angioedema, a potentially life threatening condition. Show less
