TY - JOUR

T1 - PvdM of fluorescent pseudomonads is required for the oxidation of ferribactin by PvdP in periplasmic pyoverdine maturation

AU - Sugue, Michael-Frederick

AU - Burdur, Ali Nazmi

AU - Ringel, Michael Thomas

AU - Dräger, Gerald

AU - Brüser, Thomas

N1 - Funding Information: We gratefully acknowledge the skillful technical assistance of Sybille Traupe, Katrin Gunka, and Inge Reupke (Leibniz University Hannover). T. B. conceptualization; M.-F. S. and M. T. R. methodology; M.-F. S. validation; M.-F. S. A. N. B. G. D. and T. B. investigation; T. B. writing–original draft; M.-F. S. A. N. B. M. T. R. G. D. and T. B. writing–review & editing; M.-F. S. and T. B. visualization; T. B. supervision; T. B. funding acquisition. This work was supported by grant BR 2285/7-1 of the German Research Foundation (DFG) to T. B.

PY - 2022/8

Y1 - 2022/8

N2 - Fluorescent pseudomonads such as Pseudomonas aeruginosa or Pseudomonas fluorescens produce pyoverdine siderophores that ensure iron-supply in iron-limited environments. After its synthesis in the cytoplasm, the nonfluorescent pyoverdine precursor ferribactin is exported into the periplasm, where the enzymes PvdQ, PvdP, PvdO, PvdN, and PtaA are responsible for fluorophore maturation and tailoring steps. While the roles of all these enzymes are clear, little is known about the role of PvdM, a human renal dipeptidase–related protein that is predicted to be periplasmic and that is essential for pyoverdine biogenesis. Here, we reveal the subcellular localization and functional role of PvdM. Using the model organism P. fluorescens, we show that PvdM is anchored to the periplasmic side of the cytoplasmic membrane, where it is indispensable for the activity of the tyrosinase PvdP. While PvdM does not share the metallopeptidase function of renal dipeptidase, it still has the corresponding peptide-binding site. The substrate of PvdP, deacylated ferribactin, is secreted by a ΔpvdM mutant strain, indicating that PvdM prevents loss of this periplasmic biosynthesis intermediate into the medium by ensuring the efficient transfer of ferribactin to PvdP in vivo. We propose that PvdM belongs to a new dipeptidase-related protein subfamily with inactivated Zn 2+ coordination sites, members of which are usually genetically linked to TonB-dependent uptake systems and often associated with periplasmic FAD-dependent oxidoreductases related to D-amino acid oxidases. We suggest that these proteins are necessary for selective binding, exposure, or transfer of specific D- and L-amino acid–containing peptides and other periplasmic biomolecules in manifold pathways.

AB - Fluorescent pseudomonads such as Pseudomonas aeruginosa or Pseudomonas fluorescens produce pyoverdine siderophores that ensure iron-supply in iron-limited environments. After its synthesis in the cytoplasm, the nonfluorescent pyoverdine precursor ferribactin is exported into the periplasm, where the enzymes PvdQ, PvdP, PvdO, PvdN, and PtaA are responsible for fluorophore maturation and tailoring steps. While the roles of all these enzymes are clear, little is known about the role of PvdM, a human renal dipeptidase–related protein that is predicted to be periplasmic and that is essential for pyoverdine biogenesis. Here, we reveal the subcellular localization and functional role of PvdM. Using the model organism P. fluorescens, we show that PvdM is anchored to the periplasmic side of the cytoplasmic membrane, where it is indispensable for the activity of the tyrosinase PvdP. While PvdM does not share the metallopeptidase function of renal dipeptidase, it still has the corresponding peptide-binding site. The substrate of PvdP, deacylated ferribactin, is secreted by a ΔpvdM mutant strain, indicating that PvdM prevents loss of this periplasmic biosynthesis intermediate into the medium by ensuring the efficient transfer of ferribactin to PvdP in vivo. We propose that PvdM belongs to a new dipeptidase-related protein subfamily with inactivated Zn 2+ coordination sites, members of which are usually genetically linked to TonB-dependent uptake systems and often associated with periplasmic FAD-dependent oxidoreductases related to D-amino acid oxidases. We suggest that these proteins are necessary for selective binding, exposure, or transfer of specific D- and L-amino acid–containing peptides and other periplasmic biomolecules in manifold pathways.

KW - Pseudomonas aeruginosa

KW - Pseudomonas fluorescens

KW - bacterial metabolism

KW - biosynthesis

KW - membrane protein

KW - periplasm

KW - pyoverdine maturation

KW - siderophore

UR - http://www.scopus.com/inward/record.url?scp=85134800039&partnerID=8YFLogxK

U2 - 10.1016/j.jbc.2022.102201

DO - 10.1016/j.jbc.2022.102201

M3 - Article

VL - 298

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 8

M1 - 102201

ER -