MACROMOLECULAR STRUCTURE DETERMINATION BY ELECTRON-MICROSCOPY - NEW ADVANCES AND RECENT RESULTS

Electron microscopy is undergoing a mini-renaissance, as a number of b iological systems are yielding to higher resolution analysis as a resu lt of advances in instrumentation, specimen preparation and image-proc essing technology. The atomic structure of tubulin has now been solved , crucial elements of secondary structure have recently been revealed in several membrane proteins (rhodopsin, gap junctions, aquaporin, and Ca2+ and H+ ATPases) and in a virus particle, and macromolecular comp lexes are being seen in increasingly fine detail. This growth has been enhanced further by the ability to combine structures of macromolecul ar complexes derived by electron microscopy with X-ray structures of t heir components, in order to reconstruct molecular machines and large multiprotein complexes in immense detail.