Javier Terán F, Alvarez M, Suárez J E, Mendoza M C
Facultad de Medicina, Universidad de Oviedo, Spain.
J Antimicrob Chemother. 1991 Sep;28(3):333-46. doi: 10.1093/jac/28.3.333.
Two genes encoding for aminoglycoside-(3)-N-acetyltransferases (AAC(3)s) of different substrate patterns, present in multiresistance plasmids of hospital strains of Serratia marcescens and Escherichia coli isolated from urine, have been cloned and characterized. The first, aacC1 with AAC(3)I activity, contained a 531 base pair open reading frame which encodes a polypeptide of 177 aminoacids and 19,392 daltons, confirmed by minicell analysis. Its sequence differed from previously published work in four positions. Three of the changes did not alter the aminoacid sequence while the fourth was a substitution of an alanine by a proline. The second gene, an AAC(3)II encoded by aacC2, resulted from the translation of an 858 base pair open reading frame, which encoded a 286 aminoacid polypeptide of 31,574 daltons and was identical to those from plasmids isolated in Germany and the United States. However, the homology was broken in a position between the -10 and -35 promoter sequences, which resulted in different -35 hexanucleotides and levels of resistance conferred. The assay of both genes as molecular probes has revealed their specificity with respect to other aac genes, although their usefulness was limited in the case of aacC1 derived sequences to isolated plasmid DNA, since it hybridized under stringent conditions with chromosomal DNA of some strains of E. coli.
从尿液中分离出的粘质沙雷氏菌和大肠杆菌医院菌株的多重耐药质粒中存在两种编码不同底物模式的氨基糖苷 -（3）-N - 乙酰基转移酶（AAC(3)s）的基因，已被克隆和表征。第一个基因是具有AAC(3)I活性的aacC1，包含一个531个碱基对的开放阅读框，编码一个177个氨基酸、19392道尔顿的多肽，经小细胞分析证实。其序列与先前发表的工作在四个位置不同。其中三个变化未改变氨基酸序列，而第四个变化是丙氨酸被脯氨酸取代。第二个基因是由aacC2编码的AAC(3)II，由一个858个碱基对的开放阅读框翻译而来，该阅读框编码一个286个氨基酸、31574道尔顿的多肽，与从德国和美国分离的质粒中的多肽相同。然而，在 -10和 -35启动子序列之间的一个位置上同源性被打破，这导致了不同的 -35六核苷酸和所赋予的抗性水平。将这两个基因作为分子探针进行检测，揭示了它们相对于其他aac基因的特异性，尽管对于源自aacC1的序列，其用途仅限于分离的质粒DNA，因为它在严格条件下与一些大肠杆菌菌株的染色体DNA杂交。
