<p>Under conditions of extreme acidity, the lysine-specific permease, LysP, not only mediates the import of L-lysine it also interacts with the transcriptional regulator, CadC, to activate expression of the <i>cadAB</i> operon. This operon encodes the lysine decarboxylase, CadA, which converts lysine to cadaverine while consuming a cytoplasmic proton, and the antiporter, CadB, which exports protonated cadaverine in exchange for extracellular lysine. Together, these processes contribute to cytoplasmic pH homeostasis and support bacterial acid resistance - a mechanism essential for the survival of pathogenic bacteria in acidic host environments. Here, we present the cryo-EM structure of LysP from <i>Pseudomonas aeruginosa</i> in an inward-occluded conformation (3.2–5.3 Å resolution), bound to L-lysine and a nanobody. L-Lysine is coordinated by hydrophobic contacts, cation–π interactions, and by hydrogen bonding mostly with polar uncharged residues. Reconstitution of LysP into proteoliposomes confirms specific L-lysine transport, which is competitively inhibited by L-4-thialysine. These findings provide a structural framework for understanding selective lysine recognition and inhibition, with implications for antibacterial drug design.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Structural basis of specific lysine transport by Pseudomonas aeruginosa permease LysP

  • Deniz Bicer,
  • Rei Matsuoka,
  • Aurélien F. A. Moumbock,
  • Preethi Sukumar,
  • Albert Suades,
  • Harish Cheruvara,
  • Andrew Quigley,
  • David Drew,
  • Els Pardon,
  • Jan Steyaert,
  • Peter J. F. Henderson,
  • Martin Caffrey,
  • Julia J. Griese,
  • Emmanuel Nji

摘要

Under conditions of extreme acidity, the lysine-specific permease, LysP, not only mediates the import of L-lysine it also interacts with the transcriptional regulator, CadC, to activate expression of the cadAB operon. This operon encodes the lysine decarboxylase, CadA, which converts lysine to cadaverine while consuming a cytoplasmic proton, and the antiporter, CadB, which exports protonated cadaverine in exchange for extracellular lysine. Together, these processes contribute to cytoplasmic pH homeostasis and support bacterial acid resistance - a mechanism essential for the survival of pathogenic bacteria in acidic host environments. Here, we present the cryo-EM structure of LysP from Pseudomonas aeruginosa in an inward-occluded conformation (3.2–5.3 Å resolution), bound to L-lysine and a nanobody. L-Lysine is coordinated by hydrophobic contacts, cation–π interactions, and by hydrogen bonding mostly with polar uncharged residues. Reconstitution of LysP into proteoliposomes confirms specific L-lysine transport, which is competitively inhibited by L-4-thialysine. These findings provide a structural framework for understanding selective lysine recognition and inhibition, with implications for antibacterial drug design.