Three-dimensional reconstruction of macromolecular assemblies using transmission electron microscopy and 3D reconstruction softwares

Abstract

Bacteriophage P4 is a satellite phage that uses the structural proteins encoded by phage P2 but has a smaller capsid size than P2 regulated by a scaffolding protein Sid. The P4 procapsid undergoes cleavage of its major structural protein gpN to form an intermediate stage called expanded capsid. DNA packaging and other structural changes take place consequently to form a mature virion. The major part of my Masters work comprised the 3D reconstruction of the structures of procapsid and expanded capsid of the bacteriophage P4 to resolutions of ~14?? and ~27?? respectively, using Transmission electron microscopy and 3D reconstruction softwares, in order to understand the assembly and maturation process in the P4 phage. Another part of my thesis work comprises the study of the ribosome channel complex which is the protein conducting channel in the endoplasmic reticulum (ER) membrane consisting of the heterotrimeric sec61p complex and the Translocon-associated protein (TRAP), with ribosome, by adding more data to the existing data set and getting an improved map for the ribosome channel complex using 3D reconstruction softwares.