Table 3.

Alignment of the four motifs conserved in amino acid sequences of group 1 β-lactamasesa

Source (β-lactamase)Amino acid sequence at the following motif:Refer- ence(s)
FirstSecondThirdFourth
E. coli SVSKYANDAEAKTG 7
E. cloacae SISKYANDAQAKTG 3
P. aeruginosa SVSKYSNDAEGKTG 10
K. pneumoniae (FOX-1)SVSKYSNAAEAKTG 8
C. freundii SVSKYANDAE(K)bAKTG 9,22
S. marcescens SR5058-SLSK144-YSN211-DAES308-KTG 15
S. marcescens GN19450 (SST-1)SLSKYSNDAESKTGThis study
S. marcescens GN16694 (SRT-1)SLSKYSNDAKSKTGThis study
  • a The four motifs are in alignment from the upper position in their amino acid sequences.

  • b In β-lactamases with the extended substrate specificity for oxyimino cephalosporins, E was substituted for K in the third motif.