['As an approach to understanding the role of local sequence in determining protein tertiary structure, we have examined the conformation of a 23-residue peptide fragment corresponding to the structurally conserved helix-Schellman motif-helix (H-Sm-H) domain (residue 10-32) of cellular retinoic acid binding protein, along with variants designed to probe the contributions of the helix-terminating Gly23 and the hydrophobic interactions between Leu 19 and Val24 in stabilizing the Schellman motif and hence helix termination.', 'In aqueous solution, NMR data for the H-Sm-H peptide show that it samples a largely helical conformation with a break in the helix at the point of the turn in the protein. The data also establish the presence of local hydrophobic interactions and intramolecular hydrogen bonds characteristic of a Schellman motif. Absence of helix termination in trifluoroethanol, a solvent known to disrupt hydrophobic interactions, along with an analysis of H alpha chemical shifts and NOEs in the variant peptides, suggest a major role for glycine in terminating the helix, with local hydrophobic interactions further stabilizing the Schellman motif.'] Do local interactions in a Schellman motif dictate interhelical arrangement in a protein fragment?