1. ‘Figure data_main text_DRYAD.xlsx’ contains raw data for all the figures in the main text of the paper. Different sheets in the excel file correspond to different figure numbers in the paper. Likewise, ‘Figure data_supp info_DRYAD.xlsx’ contains data for figures in Supplementary Information. 2. ‘final_cooperationModel.m’ is the MATLAB script file which was used to generate density dependent dynamics in Figure 4c. 3. The paired-end raw sequencing data for whole genome sequencing of DNAJ1, DNAJ2 and 6 WT clones (listed in Supplementary Table 2) are in the compressed file ‘Raw whole genome sequencing data for mutualism paper.zip’.