title: Structural basis for targeting the ribosomal protein S1 of Mycobacterium tuberculosis by pyrazinamide.
abstract: Pyrazinamide (PZA) is a first-line drug for tuberculosis (TB) treatment and is responsible for shortening the duration of TB therapy. The mode of action of PZA remains elusive. RpsA, the ribosomal protein S1 of Mycobacterium tuberculosis (Mtb), was recently identified as a target of PZA based on its binding activity to pyrazinoic acid (POA), the active form of PZA. POA binding to RpsA led to the inhibition of trans-translation. However, the nature of the RpsA-POA interaction remains unknown. Key questions include why POA exhibits an exquisite specificity to RpsA of Mtb and how RpsA mutations confer PZA resistance. Here, we report the crystal structures of the C-terminal domain of RpsA of Mtb and its complex with POA, as well as the corresponding domains of two RpsA variants that are associated with PZA resistance. Structural analysis reveals that POA binds to RpsA through hydrogen bonds and hydrophobic interactions, mediated mainly by residues (Lys303, Phe307, Phe310 and Arg357) that are essential for tmRNA binding. Conformational changes induced by mutation or sequence variation at the C-terminus of RpsA abolish the POA binding activity. Our findings provide insights into the mode of action of PZA and molecular basis of PZA resistance associated with RpsA mutations.
authors.affiliation: MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Fudan University, Shanghai, 200433, China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Yang
authors.forename: Yindi
authors.initials: Y
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Bi
authors.forename: Qixu
authors.initials: Q
authors.lastname: Cai
authors.forename: Xinli
authors.initials: X
authors.lastname: Liao
authors.forename: Wenqian
authors.initials: W
authors.lastname: Li
authors.forename: Chenyun
authors.initials: C
authors.lastname: Guo
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Tianwei
authors.initials: T
authors.lastname: Lin
authors.forename: Yufen
authors.initials: Y
authors.lastname: Zhao
authors.forename: Honghai
authors.initials: H
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Xuelian
authors.initials: X
authors.lastname: Zhang
authors.forename: Donghai
authors.initials: D
authors.lastname: Lin
mesh_terms: D000995:Antitubercular Agents / Q000378:metabolism / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics; D017434:Protein Structure, Tertiary; D011718:Pyrazinamide / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*; D012329:RNA, Bacterial / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D013816:Thermodynamics
chemical_list: D000995:Antitubercular Agents; D012329:RNA, Bacterial; D012269:Ribosomal Proteins; C015494:ribosomal protein S1; C096222:tmRNA; D011718:Pyrazinamide; C005296:pyrazinoic acid