Calculation of average gnomAD frequencies and activity of ADRB2 mutants from deep mutational scan

gnomAD missense variant frequencies were downloaded for six GPCRs (ADRB2, ADORA2A, ADORA1, HTR1B, CHRM1, HTR2A) directly from the gnomAD 3.1 web portal (https://gnomad.broadinstitute.org/). Missense variants at the GPCR positions identified in the relevant G protein selective LDA code were identified, and we calculated the mean frequency of variation across each of these positions for each receptor. We then calculated the average frequency of variation across all the remaining residue positions within each receptor to determine the relative abundance of mutations at the selective GPCR positions within the representation of the general population.

For the analysis of ADRB2 deep mutational scan data, we obtained the dataset of processed mutant activity data from the Jones et al. 2020 eLife⁴⁴ “Additional files” repository. The data were stratified into each of the tested concentrations and reported for each amino acid mutant at every ADRB2 residue position. We calculated the activity of the ADRB2 mutants stimulated at the EC₁₀₀ (625 nM) concentration of isoproterenol for the Gs-selective residue positions found within the Gs-selective LDA spatiotemporal code, and we calculated the global average of mutant activity at each residue position across the entire dataset. Results were plotted using ggplot2_3.3.6 in R.