Staphylococcus aureus Mutants Lacking the LytR-CpsA-Psr Family of Enzymes Release Cell Wall Teichoic Acids into the Extracellular Medium

<jats:title>ABSTRACT</jats:title> <jats:p> The LytR-CpsA-Psr (LCP) proteins are thought to transfer bactoprenol-linked biosynthetic intermediates of wall teichoic acid (WTA) to the peptidoglycan of Gram-positive bacteria. In <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">Bacillus subtilis</jats:named-content> , mutants lacking all three LCP enzymes do not deposit WTA in the envelope, while <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">Staphylococcus aureus</jats:named-content> Δ <jats:italic>lcp</jats:italic> mutants display impaired growth and reduced levels of envelope phosphate. We show here that the <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">S. aureus</jats:named-content> Δ <jats:italic>lcp</jats:italic> mutant synthesized WTA yet released ribitol phosphate polymers into the extracellular medium. Further, Δ <jats:italic>lcp</jats:italic> mutant staphylococci no longer restricted the deposition of LysM-type murein hydrolases to cell division sites, which was associated with defects in cell shape and increased autolysis. Mutations in <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">S. aureus</jats:named-content> WTA synthesis genes ( <jats:italic>tagB</jats:italic> , <jats:italic>tarF</jats:italic> , or <jats:italic>tarJ2</jats:italic> ) inhibit growth, which is attributed to the depletion of bactoprenol, an essential component of peptidoglycan synthesis (lipid II). The growth defect of <jats:italic>S. aureus tagB</jats:italic> and <jats:italic>tarFJ</jats:italic> mutants was alleviated by inhibition of WTA synthesis with tunicamycin, whereas the growth defect of the Δ <jats:italic>lcp</jats:italic> mutant was not relieved by tunicamycin treatment or by mutation of <jats:italic>tagO</jats:italic> , whose product catalyzes the first committed step of WTA synthesis. Further, sortase A-mediated anchoring of proteins to peptidoglycan, which also involves bactoprenol and lipid II, was not impaired in the Δ <jats:italic>lcp</jats:italic> mutant. We propose a model whereby the <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">S. aureus</jats:named-content> Δ <jats:italic>lcp</jats:italic> mutant, defective in tethering WTA to the cell wall, cleaves WTA synthesis intermediates, releasing ribitol phosphate into the medium and recycling bactoprenol for peptidoglycan synthesis. </jats:p>