To observe the sequence conservation position 121, the amino acid sequence for SyrB2 was used as a query for a BLAST search in the non-redundant protein database with a e -5 cutoff, resulting in 846 hits. Sequences were aligned using the MUSCLE algorithm and visualized using the AliView software. Results were filtered between the halogenases (HXA/G motif, 186 sequences) and hydroxylases (HXD/E motif, 660 sequences). Each of the sequence groups were subjected to cluster analysis using the CD-HIT web server to remove redundant sequences of 90% similarity (resulting in 132 halogenase sequences and 503 hydroxylase sequences). Individual halogenase/hydroxylase sequences were realigned with MUSCLE. LOGOS plots were generated for each cluster using WebLogo ().