primary structure

https://doi.org/10.1351/goldbook.P04843
In the context of macromolecules such as proteins, constitutional formula, usually abbreviated to a statement of the sequence and if appropriate cross-linking of chains.
See also: secondary structure, tertiary structure, quaternary structure
Source:
PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2213 (https://doi.org/10.1351/pac199668122193)
See also:
White Book, 2nd ed., p. 80 (https://iupac.qmul.ac.uk/bibliog/white.html)