title: Secondary structure and dynamics of an intrinsically unstructured linker domain.
abstract: The transient secondary structure and dynamics of an intrinsically unstructured linker domain from the 70 kDa subunit of human replication protein A was investigated using solution state NMR. Stable secondary structure, inferred from large secondary chemical shifts, was observed for a segment of the intrinsically unstructured linker domain when it is attached to an N-terminal protein interaction domain. Results from NMR relaxation experiments showed the rotational diffusion for this segment of the intrinsically unstructured linker domain to be correlated with the N-terminal protein interaction domain. When the N-terminal domain is removed, the stable secondary structure is lost and faster rotational diffusion is observed. The large secondary chemical shifts were used to calculate phi and psi dihedral angles and these dihedral angles were used to build a backbone structural model. Restrained molecular dynamics were performed on this new structure using the chemical shift based dihedral angles and a single NOE distance as restraints. In the resulting family of structures a large, solvent exposed loop was observed for the segment of the intrinsically unstructured linker domain that had large secondary chemical shifts.
authors.affiliation: Department of Microbiology, Molecular Biology, and Biochemistry, University of Idaho, Life Science South, Rm. 142, Moscow, ID 83844-3052, USA.
authors.forename: Katie E
authors.initials: KE
authors.lastname: Olson
authors.forename: Pranesh
authors.initials: P
authors.lastname: Narayanaswami
authors.forename: Pamela D
authors.initials: PD
authors.lastname: Vise
authors.forename: David F
authors.initials: DF
authors.lastname: Lowry
authors.forename: Marc S
authors.initials: MS
authors.lastname: Wold
authors.forename: Gary W
authors.initials: GW
authors.lastname: Daughdrill
mesh_terms: D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D051716:Replication Protein A
chemical_list: D004268:DNA-Binding Proteins; C497167:RPA1 protein, human; D011994:Recombinant Proteins; D051716:Replication Protein A