Fig. 4From: A single amino acid substitution in aromatic hydroxylase (HpaB) of Escherichia coli alters substrate specificity of the structural isomers of hydroxyphenylacetateGeometric comparsion of 379th position of E. coli HpaB with different amino acid residues. a The geometry of Arg379 determined from the published crystal structure of E. coli HpaB (PDB ID: 6 EB0). b Geometry of Cys379 predicted from homology modeling. The brown circle indicates the site where 4HPA and FAD bind, and the purple circle denotes the extra binding region of 4HPA [15, 24]. 4HPA (colored yellow) bindings were identified using the crystal structure of the HpaB–FAD–4HPA complex from T. thermophilus HB8 (PDB ID: 2YYJ). Distance between Ser462 in the C-terminal helical arm to Arg379 or Cys379 were predicted to be 2.70 Å and 4.75 Å, respectively.Back to article page