Analysis of the size and shape of protein complexes from yeast

Abstract

This chapter presents the analysis of the size and shape of protein complexes from yeast and describes the way for estimating the molecular weight and shape of soluble proteins from yeast. These estimates—when coupled with epitope tagging and coimmunoprecipitation—give insight into the physical properties and molecular makeup of protein complexes. These estimates can also be very informative when pure recombinant protein is compared with the native protein. The strength of these methods rests in the fact that knowledge of only a single biochemical activity—even as simple as a western blot—is sufficient to gain some insight into molecular composition and structure. These methods may also be applied to biological complexes with mixed classes of components such as protein–RNA complexes. The results of size and shape measurement are quantitative, and thus can be compared directly with previously determined experimental values. Such comparisons can be very powerful and can provide insight into molecular structure and function.