Streptococcus pneumoniae (the pneumococus), a superbug bacteria, is a leading cause of bacterial sepsis and the most frequent ethiologic-agent in the community adquired pneumoniae and non-epidemic bacterial meningitis. LytB, a member of the family of pneumococcal choline-binding protein, is responsible for the physical separation of daugther cells after division and participates in nasopharinx colonization and invasion, biofilm formation and evasion from the host immunity. Because of this, LytB is considered a putative vaccine/drug target. Here, IQFR and CIB investigators, in collaboration with scientists from the Universities of Newcastle (Newcastle upon Tyne, UK) and Notre Dame (Indiana, USA), have shown that LytB is a glucosaminidase and the basis for its high substrate specificity are unveiled. The catalytic mechanism and model of binding to the bacterial peptidoglycan together with determinants of its polar localization on pneumococcal cells is also advanced. Reported data provide a better understanding of the complex physiological role played by LytB in the bacterium and the host-pathogen interaction.

Rico-Lastres P, Díez-Martínez R, Iglesias-Bexiga M, Bustamante N, Aldridge C, Hesek D, Lee M, Mobashery S, Gray J, Vollmer W, García P, Menéndez M. 2015. “Substrate recognition and catalysis by LytB, a pneumococcal peptidoglycan hydrolase involved in virulence”. Sci Rep. 5:16198. doi: 10.1038/srep16198.