Scientists from the IQFR and University of Greifswald publish in the journal JMB the structure of PnrA, a protein of the ABC-transporter system that binds different types of nucleotides and reveal its involvement in virulence

Nucleotides are essential for key processes in bacteria such as RNA and DNA synthesis. The pathogen Streptococcus pneumoniae produces a nucleoside-binding protein, PnrA, integrated into an ABC-transporter for their uptake. In this study, the binding of pyrimidine and purine-based ribonucleosides in PnrA has been structurally characterized, being the first time that the keys for the selectivity of a nucleoside-binding protein have been described. The conjunction of a conserved pattern of interactions and the plasticity of a loop of the binding site allows its adaptation for the anchoring of different substrates. Structural analysis indicates that purine bases are bound with higher affinity, agreeing with the thermophoresis experiments. Through this work, the important role of PnrA in the Streptococcus pneumoniae infection process has been elucidated: PnrA-defective mutants are captured to a greater extent by macrophages, as observed by infection experiments.


Crystal structure and pathophysiological role of the pneumococcal nucleoside-binding protein PnrA.

Abdullah, M. R.; Batuecas, M. T.; Jennert, F.; Voβ, F.; Westhoff, P.; Kohler, T. P.; Molina, R.; Hirschmann, S.; Lalk, M.; Hermoso, J. A. & Hammerschmidt, S.

Journal of Molecular Biology (2020)