Crystal Structure of P22 Tailspike Protein: Interdigitated Subunits in a Thermostable Trimer

• DOI: 10.1126/science.8023158
• Publication Date: 2006-10-06T00:01:25Z
• Authors: Stefan Steinbacher; Robert Seckler; Stefan Miller; Boris Steipe; Robert Huber; Peter Reinemer
• Keywords: Models, Molecular; Protein Folding; 0303 health sciences; Glycoside Hydrolases; Protein Conformation; Viral Tail Proteins; Crystallography, X-Ray; Protein Structure, Secondary; Protein Structure, Tertiary; 3. Good health; Viral Proteins; 03 medical and health sciences; Computer Graphics; Point Mutation; Crystallization; Bacteriophage P22

The tailspike protein (TSP) of Salmonella typhimurium phage P22 is a part of the apparatus by which the phage attaches to the bacterial host and hydrolyzes the O antigen. It has served as a model system for genetic and biochemical analysis of protein folding. The x-ray structure of a shortened TSP (residues 109 to 666) was determined to a 2.0 angstrom resolution. Each subunit of the homotrimer contains a large parallel β helix. The interdigitation of the polypeptide chains at the carboxyl termini is important to protrimer formation in the folding pathway and to thermostability of the mature protein.