Figure 2
From: The Lactamase Engineering Database: a critical survey of TEM sequences in public databases
The structure of TEM-1 β-lactamases (PDB entry 1BTL) with the positions of substitutions found in sequences from microbial origin. Amino acid side chains are shown in stick representation: substitutions occurring at already described positions (green), substitutions at novel positions (red), and active site residues (yellow). Residues at positions 53, 238, 248, 283 can not be seen from this view.