Tannock G W, Luchansky J B, Miller L, Connell H, Thode-Andersen S, Mercer A A, Klaenhammer T R
Department of Microbiology, University of Otago, Dunedin, New Zealand.
Plasmid. 1994 Jan;31(1):60-71. doi: 10.1006/plas.1994.1007.
Lactobacillus reuteri 100-63 contains a 9.8 kb plasmid (pGT633) encoding resistance to the macrolide-lincosamide-streptogramin (MLS) type B antibiotics. The restriction endonucleases AccI, BamHI, BclI, EcoRI, EcoRV, HhaI, HindII, HpaI, KpnI, SalI, and SspI were employed to establish a physical map of pGT633. Next, genetic transfer experiments were conducted to establish the host range of pGT633. The results revealed that pGT633 replicated autonomously and encoded constitutive resistance to erythromycin in a variety of bacterial hosts, including Bacillus subtilis BD170, Streptococcus sanguis DL1, Staphylococcus aureus RN4220, and Enterococcus faecalis 19433, as well as several Lactobacillus spp. A 2.2 kb BamHI fragment of pGT633 containing the genetic determinant (ermGT) encoding resistance to erythromycin was cloned into Escherichia coli. Determination of the nucleotide sequence of ermGT revealed a methylase gene 731 bp in length that was highly related (ca. 81% nucleotide and ca. 78% amino acid identity) to the ermC gene from S. aureus plasmid pE194. The leader sequences of ermGT and ermC were identical except for a single base change at nt 51.
罗伊氏乳杆菌100 - 63含有一个9.8 kb的质粒（pGT633），该质粒编码对B型大环内酯 - 林可酰胺 - 链阳霉素（MLS）类抗生素的抗性。使用限制性内切酶AccI、BamHI、BclI、EcoRI、EcoRV、HhaI、HindII、HpaI、KpnI、SalI和SspI构建pGT633的物理图谱。接下来，进行基因转移实验以确定pGT633的宿主范围。结果表明，pGT633在多种细菌宿主中自主复制并编码对红霉素的组成型抗性，这些宿主包括枯草芽孢杆菌BD170、血链球菌DL1、金黄色葡萄球菌RN4220、粪肠球菌19433以及几种罗伊氏乳杆菌。将pGT633中一个包含编码对红霉素抗性的遗传决定因子（ermGT）的2.2 kb BamHI片段克隆到大肠杆菌中。ermGT核苷酸序列的测定揭示了一个长度为731 bp的甲基化酶基因，该基因与金黄色葡萄球菌质粒pE194中的ermC基因高度相关（核苷酸同一性约为81%，氨基酸同一性约为78%）。ermGT和ermC的前导序列除了在第51位核苷酸处有一个单碱基变化外完全相同。
