Fig. 1

Sequence alignment of HpaB homologs. a Pairwise sequence alignment between HpaBs from E. coli BL21(DE3) and REL606 at the nucleotide and protein sequence levels. The aligned nucleotides were identical except for those at position 1135 of hpaB. b Phylogenetic tree of HpaB homologs. Multiple alignments of 20 protein sequences were performed using MUSCLE [19]. The maximum likelihood tree was built using MEGA X with bootstraps of 1000 replicates [20]. Bootstrap values (as percentages) are denoted at internal nodes. For each HpaB homolog of E. coli BL21(DE3), the BLASTP result is given as the accession number, amino acid identity, and e-value. Scale bar indicates substitution per amino acid sequence site. Amino acid residues at position 379 are shown in the box at the right