5nod
PASTA subunit 4 of Streptococcus pneumoniae STKP crystallized with PEG and succinate
Structural highlights
FunctionSTKP_STRR6 Protein kinase involved in signal transduction pathways that regulate various cellular processes. Likely senses intracellular peptidoglycan subunits present in the cell division septa of actively growing cells; thus, intracellular unlinked peptidoglycan may serve as the signal molecules that trigger StkP phosphorylation activity on a set of substrates. Plays a crucial role in the regulation of cell shape and cell division of S.pneumoniae through control of at least DivIVA activity. Identified target substrates that are specifically phosphorylated by StkP in vivo, mainly on threonine residues, are DivIVA and StkP itself. Autophosphorylated StkP is a substrate for the cotranscribed protein phosphatase PhpP (shown in the avirulent strain Rx / Cp1015); PhpP and StkP appear to constitute a functional signaling couple in vivo.[1] [2] Publication Abstract from PubMedEukaryotic-like serine/threonine kinases (eSTKs) with extracellular PASTA repeats are key membrane regulators of bacterial cell division. How PASTA repeats govern eSTK activation and function remains elusive. Using evolution- and structural-guided approaches combined with cell imaging, we disentangle the role of each PASTA repeat of the eSTK StkP from Streptococcus pneumoniae. While the three membrane-proximal PASTA repeats behave as interchangeable modules required for the activation of StkP independently of cell wall binding, they also control the septal cell wall thickness. In contrast, the fourth and membrane-distal PASTA repeat directs StkP localization at the division septum and encompasses a specific motif that is critical for final cell separation through interaction with the cell wall hydrolase LytB. We propose a model in which the extracellular four-PASTA domain of StkP plays a dual function in interconnecting the phosphorylation of StkP endogenous targets along with septal cell wall remodelling to allow cell division of the pneumococcus. PASTA repeats of the protein kinase StkP interconnect cell constriction and separation of Streptococcus pneumoniae.,Zucchini L, Mercy C, Garcia PS, Cluzel C, Gueguen-Chaignon V, Galisson F, Freton C, Guiral S, Brochier-Armanet C, Gouet P, Grangeasse C Nat Microbiol. 2017 Dec 4. pii: 10.1038/s41564-017-0069-3. doi:, 10.1038/s41564-017-0069-3. PMID:29203882[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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