Conservation and Divergence of the I-Domain Inserted into the Ubiquitous HK97 Coat Protein Fold in P22-Like Bacteriophages.

ABSTRACT: Despite very low sequence homology, the major capsid proteins of double-stranded DNA (dsDNA) bacteriophages, some archaeal viruses, and the herpesviruses share a structural motif, the HK97 fold. Bacteriophage P22, a paradigm for this class of viruses, belongs to a phage gene cluster that contains three homology groups: P22-like, CUS-3-like, and Sf6-like. The coat protein of each phage has an inserted domain (I-domain) that is more conserved than the rest of the coat protein. In P22, loops in the I-domain are critical for stabilizing intra- and intersubunit contacts that guide proper capsid assembly. The nuclear magnetic resonance (NMR) structures of the P22, CUS-3, and Sf6 I-domains reveal that they are all six-stranded, anti-parallel β-barrels. Nevertheless, significant structural differe

SUBMITTER: Tripler TN 

PROVIDER: S-EPMC6475800 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature