Co-evolution of expansin domains
For comparison of the co-occurrence of the two expansin domains, all sequence entries from the ExED were aligned against the two profile HMMs for the expansin domains. Profile-to-sequence alignments were performed with the hmmsearch command from the HMMER software suite with themax option to collect all domain-based scores for each possible alignment. The lists of domain-based scores were sorted by sequence identifiers to ensure comparability, and in case of multiple hits, only the maximal bit score was kept. The bivariate histogram was visualized as heat map for bit scores greater than zero in MATLAB (version R2019a, The MathWorks, Natick, MA, USA).