小柯机器人

美国纽约大学Evgeny Nudler等研究人员合作绘制出抗生素结合点的高分辨率图谱。相关论文于2023年8月30日在线发表在《自然》杂志上。

研究人员表示，抗生素结合位点位于重要酶的重要结构域中，抗药性突变方面的研究已经非常广泛。

研究人员利用多重基因组工程克服了这一限制，产生了一系列760个单残基突变体，涵盖了大肠杆菌RNA聚合酶（RNAP）的整个利福平结合位点，并对其进行了表征。通过绘制药物与酶相互作用的基因图谱，研究人员确定了一个α螺旋，在该区域的突变可显著增强或破坏利福平的结合。研究人员发现该区域的突变可延长抗生素的结合时间，通过诱导致命的DNA断裂将利福平从抑菌药物转化为杀菌药物。

后者依赖于复制，这表明利福平是通过在启动子上引起有害的转录-复制冲突来杀死细菌的。快速的RNAP会消耗细胞中的核苷酸，改变细胞对不同抗生素的敏感性，并提供冷生长优势。最后，通过绘制天然rpoB序列多样性图谱，研究人员发现改变RNAP特性或赋予耐药性的功能性利福平结合位点突变在自然界中经常发生。

附：英文原文

Title: High-resolution landscape of an antibiotic binding site

Author: Yang, Kevin B., Cameranesi, Maria, Gowder, Manjunath, Martinez, Criseyda, Shamovsky, Yosef, Epshtein, Vitaliy, Hao, Zhitai, Nguyen, Thao, Nirenstein, Eric, Shamovsky, Ilya, Rasouly, Aviram, Nudler, Evgeny

Issue&Volume: 2023-08-30

Abstract: Antibiotic binding sites are located in important domains of essential enzymes and have been extensively studied in the context of resistance mutations; however, their study is limited by positive selection. Using multiplex genome engineering1 to overcome this constraint, we generate and characterize a collection of 760 single-residue mutants encompassing the entire rifampicin binding site of Escherichia coli RNA polymerase (RNAP). By genetically mapping drug–enzyme interactions, we identify an alpha helix where mutations considerably enhance or disrupt rifampicin binding. We find mutations in this region that prolong antibiotic binding, converting rifampicin from a bacteriostatic to bactericidal drug by inducing lethal DNA breaks. The latter are replication dependent, indicating that rifampicin kills by causing detrimental transcription–replication conflicts at promoters. We also identify additional binding site mutations that greatly increase the speed of RNAP.Fast RNAP depletes the cell of nucleotides, alters cell sensitivity to different antibiotics and provides a cold growth advantage. Finally, by mapping natural rpoB sequence diversity, we discover that functional rifampicin binding site mutations that alter RNAP properties or confer drug resistance occur frequently in nature.

DOI: 10.1038/s41586-023-06495-6

Source: https://www.nature.com/articles/s41586-023-06495-6

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html