title: 1H, 13C and 15N NMR assignments and solution secondary structure of rat Apo-S100 beta.
abstract: The 1H, 13C and 15N NMR assignments of the backbone and side-chain resonances of rat S100 beta were made at pH 6.5 and 37 degrees C using heteronuclear multidimensional NMR spectroscopy. Analysis of the NOE correlations, together with amide exchange rate and 1H alpha, 13C alpha and 13C beta chemical shift data, provided extensive secondary structural information. Thus, the secondary structure of S100 beta was determined to comprise four helices (Leu3-Ser18, helix I; Lys29-Leu40, helix II; Gln50-Glu62, helix III; and Phe70-Ala83, helix IV), four loops (Gly19-His25, loop I; Ser41-Glu49, loop II; Asp63-Gly66, loop III; and Cys84-Glu91, loop IV) and two beta-strands (Lys26-Lys28, beta-strand I and Glu67-Asp69, beta-strand II). The beta-strands were found to align in an antiparallel manner to form a very small beta-sheet. This secondary structure is consistent with predictions that S100 beta contains two 'helix-loop-helix' Ca(2+)-binding motifs known as EF-hands. The alignment of the beta-sheet, which brings the two EF-hand domains of S100 beta into close proximity, is similar to that of several other Ca(2+)-ion-binding proteins.
authors.affiliation: Department of Biological Chemistry, University of Maryland School of Medicine, Baltimore 21201, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Amburgey
authors.forename: F
authors.initials: F
authors.lastname: Abildgaard
authors.forename: M R
authors.initials: MR
authors.lastname: Starich
authors.forename: S
authors.initials: S
authors.lastname: Shah
authors.forename: D C
authors.initials: DC
authors.lastname: Hilt
authors.forename: D J
authors.initials: DJ
authors.lastname: Weber
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002135:Calcium-Binding Proteins / Q000737:chemistry*; D002247:Carbon Isotopes; D016384:Consensus Sequence; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000737:chemistry*; D009587:Nitrogen Isotopes; D017433:Protein Structure, Secondary; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D002135:Calcium-Binding Proteins; D002247:Carbon Isotopes; D009414:Nerve Growth Factors; D009587:Nitrogen Isotopes; D011994:Recombinant Proteins; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D006859:Hydrogen