title: Identification of the binding site on S100B protein for the actin capping protein CapZ.
abstract: The calcium-binding protein S100B binds to several potential target proteins, but there is no detailed information showing the location of the binding site for any target protein on S100B. We have made backbone assignments of the calcium-bound form of S100B and used chemical-shift changes in spectra of 15N-labeled protein to locate the site that binds a peptide corresponding to residues 265-276 from CapZ alpha, the actin capping protein. The largest chemical-shift changes are observed for resonances arising from residues around the C terminus of the C-terminal helix of S100B and residues Val-8 to Asp-12 of the N-terminal helix. These residues are close to but not identical to residues that have been identified by mutational analysis to be important in other S100 protein-protein interactions. They make up a patch across the S100B dimer interface and include some residues that are quite buried in the structure of calcium-free S100B. We believe we may have identified a binding site that could be common to many S100 protein-protein interactions.
authors.affiliation: Department of Biochemistry and Biological NMR Centre, University of Leicester, United Kingdom. peter.kilby@roche.com
authors.forename: P M
authors.initials: PM
authors.lastname: Kilby
authors.forename: L J
authors.initials: LJ
authors.lastname: Van Eldik
authors.forename: G C
authors.initials: GC
authors.lastname: Roberts
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D051347:CapZ Actin Capping Protein; D019281:Dimerization; D009682:Magnetic Resonance Spectroscopy; D008840:Microfilament Proteins; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000737:chemistry* / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D017433:Protein Structure, Secondary; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D013050:Spectrometry, Fluorescence
chemical_list: D002135:Calcium-Binding Proteins; D051347:CapZ Actin Capping Protein; D008840:Microfilament Proteins; D009124:Muscle Proteins; D009414:Nerve Growth Factors; D010446:Peptide Fragments; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D002118:Calcium