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bioRxiv · 10.1101/2022.06.01.494439

Roles of RodZ and Class A PBP1b in the Assembly and Regulation of the Peripheral Peptidoglycan Elongasome in Ovoid-Shaped Cells of Streptococcus pneumoniae D39

Lamanna, M. M.·Manzoor, I.·Joseph, M.·Ye, Z. A.·Benedet, M.·Zanardi, A.·Ren, Z.·Wang, X.·Massidda, O.·Tsui, H.-C. T.·Winkler, M. E.
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Abstract

RodZ of rod-shaped bacteria functions to link MreB filaments to the Rod peptidoglycan (PG) synthase complex that moves circumferentially perpendicular to the long cell axis, creating hoop-like sidewall PG. Ovoid-shaped bacteria, such as Streptococcus pneumoniae (pneumococcus; Spn) that lack MreB, use a different modality for peripheral PG elongation that emanates from the midcell of dividing cells. Yet, S. pneumoniae encodes a RodZ homolog similar to RodZ in rod-shaped bacteria. We show here that the helix-turn-helix and transmembrane domains of RodZ(Spn) are essential for growth at 37{degrees}C. {Delta}rodZ mutations are suppressed by {Delta}pbp1a, mpgA(Y488D), and {Delta}khpA mutations that suppress {Delta}mreC, but not {Delta}cozE. Consistent with a role in PG elongation, RodZ(Spn) co-localizes with MreC and aPBP1a throughout the cell cycle and forms complexes and interacts with PG elongasome proteins and regulators. Depletion of RodZ(Spn) results in aberrantly shaped, non-growing cells and mislocalization of elongasome proteins MreC, PBP2b, and RodA. Moreover, Tn-seq reveals that RodZ(Spn), but not MreCD(Spn), displays a specific synthetic-viable genetic relationship with aPBP1b, whose function is unknown. We conclude that RodZ(Spn) acts as a scaffolding protein required for elongasome assembly and function and that aPBP1b, like aPBP1a, plays a role in elongasome regulation and possibly peripheral PG synthesis. Graphical Summary O_FIG O_LINKSMALLFIG WIDTH=192 HEIGHT=200 SRC="FIGDIR/small/494439v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@f1cfb9org.highwire.dtl.DTLVardef@17cac68org.highwire.dtl.DTLVardef@1af20borg.highwire.dtl.DTLVardef@108d83c_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Lamanna, M. M., Manzoor, I., Joseph, M., Ye, Z. A., Benedet, M., Zanardi, A., Ren, Z., Wang, X., Massidda, O., Tsui, H.-C. T., Winkler, M. E.. 2022-06-02. Roles of RodZ and Class A PBP1b in the Assembly and Regulation of the Peripheral Peptidoglycan Elongasome in Ovoid-Shaped Cells of Streptococcus pneumoniae D39. https://doi.org/10.1101/2022.06.01.494439

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