THE STRUCTURE OF MENGO VIRUS AT 3.0 ANGSTROM RESOLUTION
Abstract
Mengo virus represents the cardioviruses, a genus of picornaviruses, which are different from human rhinovirus 14 and poliovirus in thermostability, antigenicity, and host receptor recognition. An orthorhombic crystal form of Mengo virus was obtained and these crystals can diffract x-rays to 2.2 A resolution. High quality diffraction data were collected at the Cornell High Energy Synchrotron Source (CHESS), using these crystals and the oscillation photography techniques. The film processing and following structure determination were carried out with the CYBER 205 supercomputer. The structure was determined to 3.0 A resolution and an atomic model was built into the electron density map using the Evans and Sutherland PS300 computer graphics system and the FRODO program. In the process of the Mengo virus structure determination, the molecular replacement phase extension was carried to a new limit: the complete structure of Mengo virus was determined without use of the isomorphous replacement techniques. The initial phasing model at 8.0 A resolution was constructed with the atomic coordinates of the human rhinovirus 14 structure. A comparison of the Mengo virus and human rhinovirus 14 structures gave many interesting conclusions about virus evolution and biological functions of picornaviruses. The structure of Mengo virus also helps to understand some other picornaviruses which have a closer relationship to Mengo virus than to human rhinovirus 14 or poliovirus, such as encephalomyocarditis virus, foot-and-mouth disease virus, hepatitis A virus, and Theiler's virus. The success of the molecular replacement phase extension procedure gives promise that many other virus structures also can be determined without the use of the isomorphous replacement techniques.
Degree
Ph.D.
Subject Area
Biology
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