STRUCTURE OF A NOVEL OXIDOREDUCTASE (TETX) IN TETRACYCLINE DRUG RESISTANCE

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 自20世纪40年代发现以来，四环素类抗生素已被广泛用于对抗各种革兰氏阳性、革兰氏阴性和更不寻常的靶标，如衣原体和支原体。除了经典的医药应用外，金霉素和土霉素通常以亚治疗水平用于动物饲料中作为生长剂。 随着四环素类抗生素成为生产最广泛的抗生素，耐药细菌的数量也在增加，以至于它们在临床和农业环境中几乎无处不在。耐药性通常由药物外排（tetA）或核糖体保护（tetM和tetO）引起。最近，通过药物失活（tetX）发现了一种新的耐药酶机制。我们已经找到了tetX的结晶条件，并正在请求收集MAD数据集的射束时间。非常小的天然晶体在CHESS F1衍射到2.6 A（晶体由同事拍摄，但由于冻结不良而无法收集数据）。这些冻结问题已经得到解决。 我们希望收集tetX蛋白的天然和MAD数据集以及药物复合物的浸泡。我们的研究特别相关，因为FDA最近批准的抗生素之一是Tygacil。或替吉环素，四环素类的一员，很容易被tetX灭活。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Since their discovery in the 1940s, the tetracycline class of antibiotics has been widely used against a broad range of Gram positive, Gram negative and more unusual targets such as Chlamydia and mycoplasmas. In addition to classic medicinal applications, chlortetracycline and oxytetracycline are commonly used at sub-therapeutic levels in animal feed as growth. As the tetracyclines have risen to become the most widely produced antibiotic, the number of resistant bacteria has increased to the point that they are nearly ubiquitous in clinical and agricultural settings. Resistance is typically conferred by either efflux of the drug (tetA) or ribsomal protection (tetM and tetO). Recently, a new enzymatic mechanism of resistance was discovered through drug inactivation (tetX). We have found crystallization conditions for tetX and are requesting beamtime for the collection of a MAD data set. Very small native crystals diffracted to 2.6 A at CHESS F1 (the crystal was shot by a colleague but was unable to collect data because of poor freezes). These freezing issues have since been resolved. We would like to collect both a native and MAD data set of the tetX protein as well as a soak of the drug-complex. Our studies are particularly relevant as one of the most recent antibiotics approved by the FDA is Tygacil¿¿ or tigilcycline, a member of the tetracycline class is readily inactivated by tetX.