ジャーナル: FEBS Lett / 年: 2019 タイトル: Structural and biochemical analysis of a phosin from Streptomyces chartreusis reveals a combined polyphosphate- and metal-binding fold. 著者: Sebastiaan Werten / Nils Hinnerk Rustmeier / Maximilian Gemmer / Marie-Joëlle Virolle / Winfried Hinrichs / 要旨: 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 ...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 . 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.