Bauernfeind A, Stemplinger I, Jungwirth R, Ernst S, Casellas J M
Max von Pettenkofer-Institut, Munich, Federal Republic of Germany.
Antimicrob Agents Chemother. 1996 Feb;40(2):509-13. doi: 10.1128/AAC.40.2.509.
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.
通过蛋白质测序或DNA测序确定的头孢他啶酶CTX-M-1和MEN-1的氨基酸序列是相同的，而CTX-M-2与CTX-M-1/MEN-1的序列一致性为84%。这两种β-内酰胺酶与其他质粒A类酶的亲缘关系较远（CTX-M-1/MEN-1与TEM-1的同源性为38.1%，CTX-M-2与TEM-1的同源性为36.5%）；它们与产酸克雷伯菌E23004的染色体β-内酰胺酶关系最为密切（CTX-M-1/MEN-1与该酶的同源性为74.5%，CTX-M-2与该酶的同源性为77.9%）。头孢他啶酶CTX-M-1/MEN-1和CTX-M-2代表了质粒A类β-内酰胺酶一个新亚组的两个成员。
