Median distance standard deviation is larger between domains for matched pairs in 1CFC and 1DMO.

This analysis compares distance standard deviation (SD) between and inside the two domains of calcium-free calmodulin in PDB entries 1CFC and 1DMO. For each entry, it used all 25 or 30 deposited models, respectively, and matched between-domain residue pairs to inside-domain pairs with the nearest mean distance, using a maximum gap of 0.25 Å. Among the matched subsets, the between-domain median SD was 8.6674 times the reference median in 1CFC and 4.7671 times the reference median in 1DMO. The matching retained 24.82% and 17.97% of candidate pairs, respectively. The result describes spread across these deposited coordinate models; it does not establish molecular motion, a biological cause, or an inferential effect. The pairs and models are not independent, and the study reports no p-value or confidence interval. Sensitivity, reproduction checks, source hashes, methods, and limitations are in the main text and original package.

calmodulin · protein structure · NMR · distance variability · coordinate models · mean-distance matching · standard deviation · sensitivity analysis