[SCAN] Mechanisms of peptidoglycan synthesis and hydrolysis enzymes driving the staphylococcal cell cycle
Simon Schaper
| When |
06 Apr, 2022
from
12:00 pm to 01:00 pm |
|---|---|
| Contact Name | Rita Abranches |
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Title: Mechanisms of peptidoglycan synthesis and hydrolysis enzymes driving the staphylococcal cell cycle
Speaker: Simon Schaper
Abstract: For most bacterial cells to divide, they must incorporate new cell wall material into the existing peptidoglycan (PG) sacculus at the division site. This essential process involves a set of conserved PG-metabolizing enzymes, whose activities must be coordinated in time and space. Recent advances in the study of the movement dynamics, activity and regulation of PG synthesis and hydrolysis enzymes have highlighted their importance in the context of bacterial cell cycle progression.
Using single-molecule tracking, we observed the circumferential motion of the essential PG synthesis enzyme complex around the division plane in Staphylococcus aureus cells. Enzymatic inactivation of this protein complex resulted in slower speeds and a reduced cell constriction rate. Contrarily to rod-shaped bacterial models, in S. aureus the directed motion of PG synthesis complexes is not correlated with the rate of FtsZ treadmilling.
In addition, we recently identified a positive regulator of a major PG hydrolase involved in daughter cell separation. We provide first evidence for a SMC-like integral membrane protein complex of S. aureus to dimerize upon ATP binding and interact with DNA in vitro. Its ATP-dependent enrichment at mid-cell results in the post-translational regulation of an autolytic amidase to promote the timely splitting of the division septum.
Our findings indicate that S. aureus has evolved multiple mechanisms that control the spatiotemporal distribution of active PG synthases and hydrolases and thereby ensure an orderly progression through the cell cycle.
