Evans Lindsay, Kotar Anita, Valentini Martina, Filloux Alain, Jamshidi Shirin, Plavec Janez, Rahman Khondaker Miraz, Vilar Ramon
Department of Chemistry, Imperial College London, White City Campus London W12 OBZ UK
Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19 1000 Ljubljana Slovenia.
RSC Chem Biol. 2022 Nov 15;4(1):94-100. doi: 10.1039/d2cb00205a. eCollection 2023 Jan 4.
A number of Gram-negative bacteria such as are becoming resistant to front-line antibiotics. Consequently, there is a pressing need to find alternative bio-molecular targets for the development of new drugs. Since non-canonical DNA structures such as guanine-quadruplexes (G4s) have been implicated in regulating transcription, we were interested in determining whether there are putative quadruplex-forming sequences (PQS) in the genome of . Using bioinformatic tools, we screened 36 genes potentially relevant to drug resistance for the presence of PQS and 10 of these were selected for biophysical characterisation ( circular dichroism and thermal difference UV/Vis spectroscopy). These studies showed that three of these G-rich sequences (linked to , and genes) form stable guanine-quadruplexes which were studied by NMR spectroscopy; detailed analysis of one of the sequences () confirmed that it adopts a two-quartet antiparallel quadruplex structure in the presence of K ions. We also show by FRET melting assays that small molecules can stabilise these three new G4 DNA structures under physiological conditions. These initial results could be of future interest in the development of new antibiotics with alternative bio-molecular targets which in turn would help tackle antimicrobial resistance.
许多革兰氏阴性菌，如……，正变得对一线抗生素产生耐药性。因此，迫切需要寻找新的生物分子靶点来开发新药。由于非经典DNA结构，如鸟嘌呤四链体（G4s），已被认为与转录调控有关，我们有兴趣确定……基因组中是否存在假定的四链体形成序列（PQS）。使用生物信息学工具，我们筛选了36个可能与耐药性相关的基因，以寻找PQS的存在，并选择其中10个进行生物物理表征（圆二色性和热差紫外/可见光谱）。这些研究表明，这些富含G的序列中有三个（与……、……和……基因相关）形成了稳定的鸟嘌呤四链体，并通过核磁共振光谱进行了研究；对其中一个序列（……）的详细分析证实，在钾离子存在下，它采用了双四重奏反平行四链体结构。我们还通过荧光共振能量转移熔解实验表明，小分子可以在生理条件下稳定这三种新的G4 DNA结构。这些初步结果可能对开发具有替代生物分子靶点的新型抗生素具有未来意义。这反过来将有助于应对抗菌药物耐药性。
