Download MendeleyMultiple Functional Roles of the Accessory I-Domain of Bacteriophage P22 Coat Protein Revealed by NMR Structure and CryoEM Modeling.
Rizzo, A.A., Suhanovsky, M.M., Baker, M.L., Fraser, L.C., Jones, L.M., Rempel, D.L., Gross, M.L., Chiu, W., Alexandrescu, A.T., Teschke, C.M.(2014) Structure 22: 830-841
- PubMed: 24836025
- DOI: https://doi.org/10.1016/j.str.2014.04.003
- Primary Citation of Related Structures:
2M5S - PubMed Abstract:
Some capsid proteins built on the ubiquitous HK97-fold have accessory domains imparting specific functions. Bacteriophage P22 coat protein has a unique insertion domain (I-domain). Two prior I-domain models from subnanometer cryoelectron microscopy (cryoEM) reconstructions differed substantially. Therefore, the I-domain's nuclear magnetic resonance structure was determined and also used to improve cryoEM models of coat protein. The I-domain has an antiparallel six-stranded β-barrel fold, not previously observed in HK97-fold accessory domains. The D-loop, which is dynamic in the isolated I-domain and intact monomeric coat protein, forms stabilizing salt bridges between adjacent capsomers in procapsids. The S-loop is important for capsid size determination, likely through intrasubunit interactions. Ten of 18 coat protein temperature-sensitive-folding substitutions are in the I-domain, indicating its importance in folding and stability. Several are found on a positively charged face of the β-barrel that anchors the I-domain to a negatively charged surface of the coat protein HK97-core.
Organizational Affiliation:
Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA.
