The Architecture of Folded Proteins

The sets of atomic coordinates of protein structures provide the raw material for a number of investigations aimed at elucidating the principles of protein architecture, the mechanism of folding, the dynamics of the structures (including the mechanism of function, which may be thought of as the dynamics of the interaction among proteins, substrates and cofactors) and the mechanism of protein evolution. The purpose of this article is to analyze and classify the kinds of studies now in progress in our own and other laboratories, and the kinds of questions that people would like to ask but are currently unable to answer. 

Figure 16.3 Images illustrating the architecture of a bacterial channel (KcsA). (A) Stereoview of a ribbon representation of the three-dimensional fold of the KcsA tetramer viewed from the extracellular side. The four subunits are distinguished by color. (B) Stereoview from another perspective, perpendicular to that in (A). (C) Ribbon representation of the tetramer as an integral-membrane protein. Aromatic amino acids on the membrane-facing surface are displayed in black. (D) Inverted conelike architecture of the tetramer. With permission from American Association for the Advancement of Science.

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