Conformational ensembles in Klebsiella pneumoniae FimH impact uropathogenesis

作者：Edward D. B. Lopatto, Jerome S. Pinkner, Denise A. Sanick, Robert Potter, Lily X. Liu, Jesús Bazán Villicaña, Kevin O. Tamadonfar, Yijun Ye, Maxwell I. Zimmerman, Nathaniel C. Gualberto, Karen Dodson, James W. Janetka, David A. Hunstad, Scott J. Hultgren · 发表于：Proceedings of the National Academy of Sciences · 年份：2024 · DOI：10.1073/pnas.2409655121 · 被引用次数：21 · 研究领域：Escherichia coli research studies、Urinary Tract Infections Management、Bladder and Urothelial Cancer Treatments

Klebsiella pneumoniae is an important pathogen causing difficult-to-treat urinary tract infections (UTIs). Over 1.5 million women per year suffer from recurrent UTI, reducing quality of life and causing substantial morbidity and mortality, especially in the hospital setting. Uropathogenic E. coli (UPEC) is the most prevalent cause of UTI. Like UPEC, K. pneumoniae relies on type 1 pili, tipped with the mannose-binding adhesin FimH, to cause cystitis. However, K. pneumoniae FimH is a poor binder of mannose, despite a mannose-binding pocket identical to UPEC FimH. FimH is composed of two domains that are in an equilibrium between tense (low-affinity) and relaxed (high-affinity) conformations. Substantial interdomain interactions in the tense conformation yield a low-affinity, deformed mannose-binding pocket, while domain–domain interactions are broken in the relaxed state, resulting in a high-affinity binding pocket. Using crystallography, we identified the structural basis by which domain–domain interactions direct the conformational equilibrium of K. pneumoniae FimH, which is strongly shifted toward the low-affinity tense state. Removal of the pilin domain restores mannose binding to the lectin domain, thus showing that poor mannose binding by K. pneumoniae FimH is not an inherent feature of the mannose-binding pocket. Phylogenetic analyses of K. pneumoniae genomes found that FimH sequences are highly conserved. However, we surveyed a collection of K. pneumoniae isolates from ...