title: NMR assignments for the insertion domain of bacteriophage Sf6 coat protein.
abstract: The P22 bacteriophage group is a subgroup of the λ phage supercluster, comprised of the three major sequence types Sf6, P22, and CUS-3, based on their capsid proteins. Our goal is to investigate the extent to which structure-function relationships are conserved for the viral coat proteins and I-domains in this subgroup. Sf6 is a phage that infects the human pathogen Shigella flexneri. The coat protein of Sf6 assembles into a procapsid, which further undergoes maturation during DNA packaging into an infectious virion. The Sf6 coat protein contains a genetically inserted domain, termed the I-domain, similar to the ones present in the P22 and CUS-3 coat proteins. Based on the P22 example, I-domains play important functional roles in capsid assembly, stability, viability, and size-determination. Here we report the1H,15N, and13C chemical shift assignments for the I-domain of the Sf6 phage coat protein. Chemical shift-based secondary structure prediction and hydrogen-bond patterns from a long-range HNCO experiment indicate that the Sf6 I-domain adopts a 6-stranded β-barrel fold like those of P22 and CUS-3 but with important differences, including the absence of the D-loop that is critical for capsid assembly and the addition of a novel disordered loop region.
authors: Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT, 06269-3125, USA.
authors: Therese N
authors: TN
authors: Tripler
authors: Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT, 06269-3125, USA. Carolyn.teschke@uconn.edu.|Department of Chemistry, University of Connecticut, 55 N. Eagleville Rd., Storrs, CT, 06269-3060, USA. Carolyn.teschke@uconn.edu.
authors: Carolyn M
authors: CM
authors: Teschke
authors: Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT, 06269-3125, USA. andrei@uconn.edu.
authors: Andrei T
authors: AT
authors: Alexandrescu
mesh_terms: D000595:Amino Acid Sequence; D017100:Bacteriophage P22 / Q000502:physiology*; D036022:Capsid Proteins / Q000737:chemistry* / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D000072417:Protein Domains
chemical_list: D036022:Capsid Proteins
keywords: Conserved folding motifs; Icosahedral particles; Intrinsically disordered proteins; Protein dynamics; Structure homology