dos Santos Débora Farage Knupp, Istvan Paula, Noronha Eliane Ferreira, Quirino Betânia Ferraz, Krüger Ricardo Henrique
Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, Brazil,
Biotechnol Lett. 2015 Sep;37(9):1809-17. doi: 10.1007/s10529-015-1861-x. Epub 2015 May 21.
Putative new dioxygenases were identified in a metagenomic β-lactam-resistance screening and, given their key role on aromatic metabolism, we raise the hypothesis that these enzymes maybe concomitantly related to antibiotic resistance and aromatic degradation.
ORFs of three putative dioxygenases were isolated from resistant metagenomic clones. One of them, CRB2(1), was subcloned into pET24a expression vector and subjected to downstream phenotypic and bioinformatics analyses that demonstrated the "dual effect" of our metagenomic dioxygenase, on antibiotic and aromatic resistance. Furthermore, initial characterization assays strongly suggests that CRB2(1) open-reading frame is an extradiol-dioxygenase, most probably a bicupin domain gentisate 1,2-dioxygenase. This observation is, to our knowledge, the first description of a metagenomic dioxygenase and its action on β-lactam resistance.
Unraveling the diversity of antibiotic resistance elements on the environment could not only identify new genes and mechanisms in which bacteria can resist to antibiotics, but also contribute to biotechnology processes, such as in bioremediation.
在宏基因组β-内酰胺抗性筛选中鉴定出了假定的新双加氧酶，鉴于它们在芳香族代谢中的关键作用，我们提出假说，即这些酶可能与抗生素抗性和芳香族降解同时相关。
从抗性宏基因组克隆中分离出了三种假定双加氧酶的开放阅读框。其中之一，CRB2(1)，被亚克隆到pET24a表达载体中，并进行了下游表型和生物信息学分析，这些分析证明了我们的宏基因组双加氧酶对抗生素和芳香族抗性具有“双重作用”。此外，初步表征试验强烈表明，CRB2(1)开放阅读框是一种间位双加氧酶，很可能是一种双杯形结构域龙胆酸1,2-双加氧酶。据我们所知，这一观察结果是对宏基因组双加氧酶及其对β-内酰胺抗性作用的首次描述。
揭示环境中抗生素抗性元件的多样性不仅可以鉴定细菌抗抗生素的新基因和机制，还可以为生物技术过程做出贡献，例如生物修复。
