Welcome to Cheng Lab

Welcome to Cheng Lab Our research aims to understand the structure and function of macromolecular interactions by selected model macromolecular systems. Viral structural proteins have the capacity to function both in assembly and in disassembly, which is made possible through a built-in flexibility triggered by cellular events. We observe conformational changes of viral particles at various states of their life cycle to analyze their assembly intermediates as well as the mature forms. Similarly, infectious virions can be treated with numerous conditions, e.g. receptor-mediated genome release or acid-activated membrane fusion, to observe the key steps of viral re-entry into host cells. Using electron microscopy, we apply a rapid-frozen and low-dose imaging procedure to best preserve the biological specimen in its native form. Computer image processing is developed to retrieve most of the useful signal from the low-contrast micrographs. Technical implementation of cryo-EM, cellular tomography, and computational modeling schemes also enables us to address interactions involved in complex biological molecules and/or nanoscale machines.