Fig. 1.

Multiple sequence alignment. a An unrooted phylogenetic tree showing the relationship of the Amy13A from the metagenome to five other α-amylases with high sequence similarities. The tree was constructed from the sequence similarity matrix of ClustalW and shows the position of newly isolated α-amylase Amy13A. b Amino acid alignment of the novel α-amylase from the metagenome, and high-matching sequences allowed the determination of the catalytic triad. E207 was predicted to be the active site of Amy13A. Underlined residues represent the catalytic triad, asterisks represent residues in a column that are identical in all sequences in the alignment, semicolons represent conserved substitutions, dots represent semiconserved substitutions