Pseudomonas aeruginosa regulator PvrA binds simultaneously to multiple pseudo-palindromic sites for efficient transcription activation

• Published in: Science China. Life sciences Vol. 67; no. 5; pp. 900 - 912
• Main Authors: Zhu, Yibo, Luo, Bingnan, Mou, Xingyu, Song, Yingjie, Zhou, Yonghong, Luo, Yongbo, Sun, Bo, Luo, Youfu, Tang, Hong, Su, Zhaoming, Bao, Rui
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.05.2024; Springer Nature B.V
• Subjects: Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Binding Sites; Biofilms - growth & development; Biomedical and Life Sciences; Cryoelectron Microscopy; Crystal structure; Crystallography, X-Ray; Deoxyribonucleic acid; DNA; DNA structure; DNA, Bacterial - genetics; DNA, Bacterial - metabolism; Electron microscopy; Gene Expression Regulation, Bacterial; Life Sciences; Models, Molecular; Mutation; Promoter Regions, Genetic; Protein Binding; Pseudomonas aeruginosa; Pseudomonas aeruginosa - genetics; Pseudomonas aeruginosa - metabolism; Pseudomonas aeruginosa - pathogenicity; Pyocyanin; Pyocyanine - biosynthesis; Pyocyanine - metabolism; Research Paper; Structure-function relationships; Trans-Activators - chemistry; Trans-Activators - genetics; Trans-Activators - metabolism; Transcription activation; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Transcriptional Activation; Virulence; Virulence - genetics; TetR; protein- structure; transcription regulator; virulence; Pseudomonas aeruginosa
• ISSN: 1674-7305; 1869-1889
• DOI: 10.1007/s11427-022-2363-y

Tetracycline repressor (TetR) family regulators (TFRs) are the largest group of DNA-binding transcription factors and are widely distributed in bacteria and archaea. TFRs play vital roles in controlling the expression of various genes and regulating diverse physiological processes. Recently, a TFR protein P seudomonas v irulence r egulator A (PvrA), was identified from Pseudomonas aeruginosa as the transcriptional activator of genes involved in fatty acid utilization and bacterial virulence. Here, we show that PvrA can simultaneously bind to multiple pseudo-palindromic sites and upregulate the expression levels of target genes. Cryo-electron microscopy (cryo-EM) analysis indicates the simultaneous DNA recognition mechanism of PvrA and suggests that the bound DNA fragments consist of a distorted B-DNA double helix. The crystal structure and functional analysis of PvrA reveal a hinge region that secures the correct domain motion for recognition of the promiscuous promoter. Additionally, our results showed that mutations disrupting the regulatory hinge region have differential effects on biofilm formation and pyocyanin biosynthesis, resulting in attenuated bacterial virulence. Collectively, th e se findings will improve the understanding of the relationship between the structure and function of the TetR family and provide new insights into the mechanism of regulation of P. aeruginosa virulence.