Table 2.

Amino acid substitutions in TEM-type β-lactamases

β-lactamaseAmino acid located at positiona:
39104153164182237238
TEM-1GlnGluHisArgMetAlaGly
TEM-2Lys
TEM-3LysLysSer
TEM-11LysHis
TEM-19Ser
TEM-20ThrSer
TEM-21LysLysArgSer
TEM-22LysLysGlySer
TEM-29His
• a Numbering according to Ambler et al. (2). Amino acids indicated in bold extend the spectrum of β-lactamase activity.