Ghosh Gairika, Reddy Jayavardhana, Sambhare Susmit, Sen Ranjan
Laboratory of Transcription, Center for DNA Fingerprinting and Diagnostics, Tuljaguda Complex, Nampally, Hyderabad, India.
Graduate Studies, Manipal University, Manipal, Karnataka, India.
J Bacteriol. 2017 Dec 5;200(1). doi: 10.1128/JB.00380-17. Print 2018 Jan 1.
Rho is a hexameric molecular motor that functions as a conserved transcription terminator in the majority of bacterial species and is a potential drug target. Psu is a bacteriophage P4 capsid protein that inhibits Rho by obstructing its ATPase and translocase activities. In this study, we explored the anti-Rho activity of Psu for Rho proteins from different pathogens. Sequence alignment and homology modeling of Rho proteins from pathogenic bacteria revealed the conserved nature of the Psu-interacting regions in all these proteins. We chose Rho proteins from various pathogens, including , , , , , , , , and The purified recombinant Rho proteins of these organisms showed variable rates of ATP hydrolysis on poly(rC) as the substrate and were capable of releasing RNA from the transcription elongation complexes. Psu was capable of inhibiting these two functions of all these Rho proteins. pulldown assays revealed direct binding of Psu with many of these Rho proteins. expression of induced killing of , , , and expressing Rho indicating Psu-induced inhibition of Rho proteins of these strains under physiological conditions. We propose that the "universal" inhibitory function of the Psu protein against the Rho proteins from both Gram-negative and Gram-positive bacteria could be useful for designing peptides with antimicrobial functions and that these peptides could contribute to synergistic antibiotic treatment of the pathogens by compromising the Rho functions. Bacteriophage-derived protein factors modulating different bacterial processes could be converted into unique antimicrobial agents. Bacteriophage P4 capsid protein Psu is an inhibitor of the transcription terminator Rho. Here we show that apart from antagonizing Rho, Psu is able to inhibit Rho proteins from various phylogenetically unrelated Gram-negative and Gram-positive pathogens. Upon binding to these Rho proteins, Psu inhibited them by affecting their ATPase and RNA release functions. The expression of Psu kills various pathogens, such as and species. Hence, Psu could be useful for identifying peptide sequences with anti-Rho activities and might constitute part of synergistic antibiotic treatment against pathogens.
Rho是一种六聚体分子马达，在大多数细菌物种中作为保守的转录终止子发挥作用，是一个潜在的药物靶点。Psu是一种噬菌体P4衣壳蛋白，通过阻碍其ATP酶和转位酶活性来抑制Rho。在本研究中，我们探索了Psu对来自不同病原体的Rho蛋白的抗Rho活性。对病原菌Rho蛋白的序列比对和同源建模揭示了所有这些蛋白中与Psu相互作用区域的保守性质。我们选择了来自各种病原体的Rho蛋白，包括……。这些生物体纯化的重组Rho蛋白以聚（rC）为底物显示出不同的ATP水解速率，并且能够从转录延伸复合物中释放RNA。Psu能够抑制所有这些Rho蛋白的这两种功能。下拉分析揭示了Psu与许多这些Rho蛋白的直接结合。Psu的表达诱导了表达Rho的……、……、……和……的杀伤，表明在生理条件下Psu诱导了这些菌株的Rho蛋白抑制。我们提出，Psu蛋白对革兰氏阴性菌和革兰氏阳性菌的Rho蛋白的“通用”抑制功能可用于设计具有抗菌功能的肽，并且这些肽可通过损害Rho功能来促进对病原体的协同抗生素治疗。调节不同细菌过程的噬菌体衍生蛋白因子可转化为独特的抗菌剂。噬菌体P4衣壳蛋白Psu是转录终止子Rho的抑制剂。在这里我们表明，除了拮抗Rho之外，Psu还能够抑制来自各种系统发育无关的革兰氏阴性和革兰氏阳性病原体的Rho蛋白。与这些Rho蛋白结合后，Psu通过影响其ATP酶和RNA释放功能来抑制它们。Psu的表达杀死了各种病原体，如……和……物种。因此，Psu可用于鉴定具有抗Rho活性的肽序列，并可能构成针对病原体的协同抗生素治疗的一部分。
