The type II secretion system (Xcp) of Pseudomonas putida is active and involved in the secretion of phosphatases. (26th March 2013)

• Record Type: Journal Article
• Authors: Putker, Florian; Tommassen‐van Boxtel, Ria; Stork, Michiel; Rodríguez‐Herva, José J.; Koster, Margot; Tommassen, Jan
• Is Part Of: Environmental microbiology. Volume 15:Number 10(2013:Oct.)
• Page Start: 2658
• Page End: 2671
• Publication Date: 2013-03-26
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1462-2920.12115
• Languages: English
• ISSNs: 1462-2912

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>The genome of the Gram‐negative bacterium <italic>Pseudomonas putida</italic> harbours a complete set of <italic>xcp</italic> genes for a type II protein secretion system (T2SS). This study shows that expression of these genes is induced under inorganic phosphate (P_i) limitation and that the system enables the utilization of various organic phosphate sources. A phosphatase of the PhoX family, previously designated UxpB, was identified, which was produced under low P_i conditions and transported across the cell envelope in an Xcp‐dependent manner demonstrating that the <italic>xcp</italic> genes encode an active T2SS. The signal sequence of UxpB contains a twin‐arginine translocation (Tat) motif as well as a lipobox, and both processing by leader peptidase II and Tat dependency were experimentally confirmed. Two different <italic>tat</italic> gene clusters were detected in the <italic>P. putida</italic> genome, of which one, named <italic>tat</italic><italic>‐1</italic>, is located adjacent to the <italic>uxpB</italic> and <italic>xcp</italic> genes. Both Tat systems appeared to be capable of transporting the UxpB protein. However, expression of the <italic>tat</italic><italic>‐1</italic> genes was strongly induced by low P_i levels, indicating a function of this system in survival during P_i starvation.</p> </abstract>