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Structural and biochemical analysis of a phosin from Streptomyces chartreusis reveals a combined polyphosphate‐ and metal‐binding fold
Author(s) -
Werten Sebastiaan,
Rustmeier Nils Hinnerk,
Gemmer Maximilian,
Virolle MarieJoëlle,
Hinrichs Winfried
Publication year - 2019
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.13476
Subject(s) - polyphosphate , metal , phosphate , chemistry , biopolymer , dimer , biochemistry , crystallography , metal ions in aqueous solution , biophysics , static electricity , biology , polymer , organic chemistry , engineering , electrical engineering
X‐ray crystallographic analysis of a phosin (PptA) from Steptomyces chartreusis reveals a metal‐associated, lozenge‐shaped fold featuring a 5–10 Å wide, positively charged tunnel that traverses the protein core. Two distinct metal‐binding sites were identified in which the predominant metal ion was Cu 2+ . In solution, PptA forms stable homodimers that bind with nanomolar affinity to polyphosphate, a stress‐related biopolymer acting as a phosphate and energy reserve in conditions of nutrient depletion. A single protein dimer interacts with 14–15 consecutive phosphate moieties within the polymer. Our observations suggest that PptA plays a role in polyphosphate metabolism, mobilisation or sensing, possibly by acting in concert with polyphosphate kinase (Ppk). Like Ppk, phosins may influence antibiotic synthesis by streptomycetes.