English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Background  DING proteins constitute a conserved and broadly distributed set of proteins found in bacteria, fungi, plants and animals (including humans). Characterization of DING proteins from animal and plant tissues indicated ligand-binding ability suggesting a role for DING proteins in cell signaling and biomineralization. Surprisingly, the genes encoding DING proteins in eukaryotes have not been identified in the eukaryotic genome or EST databases. Recent discovery of a DING homologue (named Psp here) in the genome of  Pseudomonas fluorescens  SBW25 provided a unique opportunity to investigate the physiological roles of DING proteins.  P. fluorescens  SBW25 is a model bacterium that can efficiently colonize plant surfaces and enhance plant health. In this report we genetically characterize Psp with a focus on conditions under which  psp  is expressed and the protein exported.    Results  Psp is closely related to the periplasmic P i  binding component of the ABC-type phosphate transporter system (Pst).  psp  is flanked by a gene cluster predicted to function as a type II protein secretion system (Hxc). Deletion analysis combined with chromosomally integrated ' lacZ  fusions showed that both  psp  and  pstC  are induced by P i  limitation and that  pstC  is required for competitive growth of the bacterium in P i  limited medium.  hxcR  is not regulated by P i  limitation. Psp was detected (using anti-DING serum) in the supernatant of wild-type culture but was greatly reduced in the supernatant of an isogenic strain carrying an  hxcR  mutation (Δ hxcR ). A promoter fusion between  hxcR  and a promoterless copy of a gene (' dapB ) essential for growth in the plant environment showed that expression of  hxcR  is elevated during colonization of sugar beet seedlings. A similar analysis of  psp  showed that it is not induced in the plant environment.    Conclusion  Psp gene is expressed under conditions of P i  limitation. It is an exoprotein secreted mainly via the Hxc type II secretion system, whose expression is elevated on plant surfaces. We propose that Psp is involved in extracellular scavenging of phosphates, which are subsequently taken up by the cell-bound Pst transport system.

Genetic characterization of psp encoding the DING protein in Pseudomonas fluorescens SBW25