Regulation of Peptidoglycan Synthesis by Outer-Membrane Proteins

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• 作者：Athanasios Typas¹ ; ⁹ ; ^{athanasios.typas@ucsf.edu} ; Manuel Banzhaf³ ; ⁹ ; Bart van den Berg van Saparoea⁴ ; ¹³ ; Jolanda Verheul⁴ ; Jacob Biboy³ ; Robert J. Nichols¹ ; ⁵ ; Matylda Zietek¹ ; Katrin Beilharz³ ; ¹⁰ ; Kai Kannenberg⁶ ; ¹¹ ; Moritz von Rechenberg⁷ ; ¹² ; Eefjan Breukink⁸ ; Tanneke den Blaauwen⁴ ; Carol A. Gross¹ ; ² ; Waldemar Vollmer³ ; ^{w.vollmer@ncl.ac.uk}
• 刊名：Cell
• 出版年：2010
• 出版时间：23 December 2010
• 年：2010
• 卷：143
• 期：7
• 页码：1097-1109
• 全文大小：2163 K

文摘

Summary

Growth of the mesh-like peptidoglycan (PG) sacculus located between the bacterial inner and outer membranes (OM) is tightly regulated to ensure cellular integrity, maintain cell shape, and orchestrate division. Cytoskeletal elements direct placement and activity of PG synthases from inside the cell, but precise spatiotemporal control over this process is poorly understood. We demonstrate that PG synthases are also controlled from outside of the sacculus. Two OM lipoproteins, LpoA and LpoB, are essential for the function, respectively, of PBP1A and PBP1B, the major E. coli bifunctional PG synthases. Each Lpo protein binds specifically to its cognate PBP and stimulates its transpeptidase activity, thereby facilitating attachment of new PG to the sacculus. LpoB shows partial septal localization, and our data suggest that the LpoB-PBP1B complex contributes to OM constriction during cell division. LpoA/LpoB and their PBP-docking regions are restricted to γ-proteobacteria, providing models for niche-specific regulation of sacculus growth.