The spatial organization (including conformation) of an entire protein molecule or other macromolecule consisting of a single chain.
See also: primary structure, secondary structure, quaternary structure
Sources:
PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2220 (https://doi.org/10.1351/pac199668122193)
White Book, 2nd ed., p. 80 (https://iupac.qmul.ac.uk/bibliog/white.html)