title: Pf1 bacteriophage hydration by magic angle spinning solid-state NMR.
abstract: High resolution two- and three-dimensional heteronuclear correlation spectroscopy ((1)H-(13)C, (1)H-(15)N, and (1)H-(13)C-(13)C HETCOR) has provided a detailed characterization of the internal and external hydration water of the Pf1 virion. This long and slender virion (2000 nm × 7 nm) contains highly stretched DNA within a capsid of small protein subunits, each only 46 amino acid residues. HETCOR cross-peaks have been unambiguously assigned to 25 amino acids, including most external residues 1-21 as well as residues 39-40 and 43-46 deep inside the virion. In addition, the deoxyribose rings of the DNA near the virion axis are in contact with water. The sets of cross-peaks to the DNA and to all 25 amino acid residues were from the same hydration water (1)H resonance; some of the assigned residues do not have exchangeable side-chain protons. A mapping of the contacts onto structural models indicates the presence of water "tunnels" through a highly hydrophobic region of the capsid. The present results significantly extend and modify results from a lower resolution study, and yield a comprehensive hydration surface map of Pf1. In addition, the internal water could be distinguished from external hydration water by means of paramagnetic relaxation enhancement. The internal water population may serve as a conveniently localized magnetization reservoir for structural studies.
authors.affiliation: Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA.
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Sergeyev
authors.affiliation: Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA.
authors.forename: Salima
authors.initials: S
authors.lastname: Bahri
authors.affiliation: Public Health Research Institute, Rutgers University, 225 Warren St., Newark, New Jersey 07103, USA.
authors.forename: Loren A
authors.initials: LA
authors.lastname: Day
authors.affiliation: Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA.
authors.forename: Ann E
authors.initials: AE
authors.lastname: McDermott
mesh_terms: D025561:Bacteriophage Pf1 / Q000737:chemistry*; D002213:Capsid / Q000737:chemistry*; D036022:Capsid Proteins / Q000737:chemistry*; D004279:DNA, Viral / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D014867:Water / Q000737:chemistry
chemical_list: D036022:Capsid Proteins; D004279:DNA, Viral; D014867:Water