当前位置: X-MOL 学术Biophys. J. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Vitamin B12-peptide nucleic acids use the BtuB receptor to pass through the E. coli outer membrane
Biophysical Journal ( IF 3.4 ) Pub Date : 2021-01-01 , DOI: 10.1016/j.bpj.2021.01.004
Tomasz Pieńko 1 , Jakub Czarnecki 2 , Marcin Równicki 3 , Monika Wojciechowska 3 , Aleksandra J Wierzba 4 , Dorota Gryko 4 , Dariusz Bartosik 5 , Joanna Trylska 3
Affiliation  

Short modified oligonucleotides that bind in a sequence-specific way to mRNA essential for bacterial growth could be useful to fight bacterial infections. One such promising oligonucleotide is peptide nucleic acid (PNA), a synthetic DNA analog with a peptide-like backbone. However, the limitation precluding the use of oligonucleotides, including PNA, is that bacteria do not import them from the environment. We have shown that vitamin B12, which most bacteria need to take up for growth, when covalently linked with PNA, delivers PNA to E. coli cells. Vitamin B12 enters E. coli via TonB-dependent transport system and is recognized by the outer-membrane vitamin B12-specific BtuB receptor. We engineered the E. coli ΔbtuB mutant and found that transport of the vitamin B12-PNA conjugate requires BtuB. Thus, the conjugate follows the same route through the outer membrane as taken by free vitamin B12. From enhanced sampling all-atom molecular dynamics simulations, we determined the mechanism of conjugate permeation through BtuB. BtuB is a β-barrel occluded by its luminal domain. The potential of mean force shows that conjugate passage is unidirectional and its movement into the BtuB β-barrel is energetically favorable upon luminal domain unfolding. Inside BtuB, PNA extends making its permeation mechanically feasible. BtuB extracellular loops are actively involved in transport through an induced-fit mechanism. We prove that vitamin B12 transport system can be hijacked to enable PNA delivery to E. coli cells.

中文翻译:

维生素 B12 肽核酸使用 BtuB 受体通过大肠杆菌外膜

以序列特异性方式与细菌生长所必需的 mRNA 结合的短修饰寡核苷酸可用于对抗细菌感染。一种这样有前途的寡核苷酸是肽核酸 (PNA),一种具有肽样骨架的合成 DNA 类似物。然而,排除使用包括 PNA 在内的寡核苷酸的限制是细菌不会从环境中输入它们。我们已经证明,大多数细菌生长需要吸收的维生素 B12 当与 PNA 共价连接时,会将 PNA 传递给大肠杆菌细胞。维生素 B12 通过 TonB 依赖性转运系统进入大肠杆菌,并被外膜维生素 B12 特异性 BtuB 受体识别。我们设计了大肠杆菌ΔbtuB 突变体,发现维生素 B12-PNA 结合物的运输需要 BtuB。因此,缀合物遵循与游离维生素 B12 相同的途径通过外膜。通过增强采样全原子分子动力学模拟,我们确定了通过 BtuB 的共轭渗透机制。BtuB 是一个被其腔域封闭的 β 桶。平均力的潜力表明共轭通道是单向的,并且在腔域展开时其进入 BtuB β-桶的运动在能量上是有利的。在 BtuB 内部,PNA 延伸使其渗透在机械上可行。BtuB 细胞外环通过诱导适合机制积极参与运输。我们证明了维生素 B12 运输系统可以被劫持以使 PNA 递送到大肠杆菌细胞。我们确定了通过 BtuB 的共轭渗透机制。BtuB 是一个被其腔域封闭的 β 桶。平均力的潜力表明共轭通道是单向的,并且在腔域展开时其进入 BtuB β-桶的运动在能量上是有利的。在 BtuB 内部,PNA 延伸使其渗透在机械上可行。BtuB 细胞外环通过诱导适合机制积极参与运输。我们证明了维生素 B12 运输系统可以被劫持以使 PNA 递送到大肠杆菌细胞。我们确定了通过 BtuB 的共轭渗透机制。BtuB 是一个被其腔域封闭的 β 桶。平均力的潜力表明共轭通道是单向的,并且在腔域展开时其进入 BtuB β-桶的运动在能量上是有利的。在 BtuB 内部,PNA 延伸使其渗透在机械上可行。BtuB 细胞外环通过诱导适合机制积极参与运输。我们证明了维生素 B12 运输系统可以被劫持以使 PNA 递送到大肠杆菌细胞。PNA 延伸使其渗透在机械上可行。BtuB 细胞外环通过诱导适合机制积极参与运输。我们证明了维生素 B12 运输系统可以被劫持以使 PNA 递送到大肠杆菌细胞。PNA 延伸使其渗透在机械上可行。BtuB 细胞外环通过诱导适合机制积极参与运输。我们证明了维生素 B12 运输系统可以被劫持以使 PNA 递送到大肠杆菌细胞。
更新日期:2021-01-01
down
wechat
bug