Sequences of beta-lactamase genes encoding CTX-M-1 (MEN-1) and CTX-M-2 and relationship of their amino acid sequences with those of other beta-lactamases.
Amino acid sequences determined either by protein sequencing or by DNA sequencing are identical for cefotaximases CTX-M-1 and MEN-1, whereas CTX-M-2 is 84% identical to CTX-M-1/MEN-1. Both beta-lactamases are distantly related to other plasmidic class A enzymes (homology to TEM-1 is 38.1% for CTX-M-1/MEN-1 and 36.5% for CTX-M-2); the closest relationship was with the chromosomal beta-lactamase of Klebsiella oxytoca E23004 (homologies of 74.5% for CTX-M-1/MEN-1 and 77.9% for CTX-M-2). The cefotaximases CTX-M-1/MEN-1 and CTX-M-2 represent two members of a new subgroup of plasmidic class A beta-lactamases.
Bauernfeind
A
A
Max von Pettenkofer-Institut, Munich, Federal Republic of Germany.
Stemplinger
I
I
Jungwirth
R
R
Ernst
S
S
Casellas
J M
JM
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis; D012486:Salmonella typhimurium / Q000201:enzymology / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
D011994:Recombinant Proteins; C071167:beta-lactamase CTX-2; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases