Analysis of carboxysome shell proteins and crystal disorders

The carboxysome is a primitive organelle composed of many small shell proteins. It is found in cyanobacteria and some chemoautotrophs. The main goals of studying the carboxysome is to understand its assembly and its mechanism of packaging molecules. The hope is that from studying the carboxysome, we can engineer our own macromolecular structures to produce and store molecules of interest. The structural determination of the proteins that compose the carboxysome shell will lead to further developments in understanding protein assembly.;This dissertation is organized into two parts and one appendix. The first part describes the determination of the structure of shell proteins in the carboxysome. In chapter one, an overview of the origins and evolution of the carboxysome is given. Chapter two describes the crystal structure of CsoS1A from Halothiobacillus neapolitanus and subsequent analysis on the carboxysome shell. Preliminary work on isolating the carboxysome to determine the sidedness of the carboxysome shell is covered in chapter three. Chapter four describes the protein expression and crystallization trials of CsoS1B, another small shell protein from H. neapolitanus. Chapter five describes the subcloning and overexpression of CsoS2, an unknown carboxysome protein, in Escherichia coli. Initial work on CcmO, a protein containing two bacterial microcompartment domains from Synechocystis PCC 6803, is covered in chapter six.;The second part of this dissertation tackles anomalies that can occur in crystals. An overview of crystal disorders is given in chapter seven. The steps for analyzing and correcting the lattice-translocation disorder found in a CsoS1C crystal is covered in chapter eight. Chapter nine describes a possible way to predict lattice-translocation disorder from intensity data. The analysis and correction of a specific type of disorder, twinning, is given in chapter ten. The appendix presents the development of a website to calculate and predict accessibility sites of a protein with known structure.