3G3Q

Crystal structure of a eukaryotic polyphosphate polymerase in complex with a phosphate polymer

Summary for 3G3Q

• Entry DOI: 10.2210/pdb3g3q/pdb
• Related: 3G3R 3G3T 3G3U 3g3o
• Descriptor: Vacuolar transporter chaperone 4, PHOSPHATE ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: polyphosphate polymerase, polyphosphate kinase, vtc complex, vacuolar transporter chaperone, tunnel enzyme, membrane, phosphoprotein, transmembrane, vacuole, biosynthetic protein
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Cellular location: Vacuole membrane; Multi-pass membrane protein: P47075
• Total number of polymer chains: 2
• Total formula weight: 72589.86

Authors

Hothorn, M.,Scheffzek, K. (deposition date: 2009-02-02, release date: 2009-05-05, Last modification date: 2023-09-06)

Primary citation

Hothorn, M.,Neumann, H.,Lenherr, E.D.,Wehner, M.,Rybin, V.,Hassa, P.O.,Uttenweiler, A.,Reinhardt, M.,Schmidt, A.,Seiler, J.,Ladurner, A.G.,Herrmann, C.,Scheffzek, K.,Mayer, A.
Catalytic core of a membrane-associated eukaryotic polyphosphate polymerase.
Science, 324:513-516, 2009

PubMed Abstract: Polyphosphate (polyP) occurs ubiquitously in cells, but its functions are poorly understood and its synthesis has only been characterized in bacteria. Using x-ray crystallography, we identified a eukaryotic polyphosphate polymerase within the membrane-integral vacuolar transporter chaperone (VTC) complex. A 2.6 angstrom crystal structure of the catalytic domain grown in the presence of adenosine triphosphate (ATP) reveals polyP winding through a tunnel-shaped pocket. Nucleotide- and phosphate-bound structures suggest that the enzyme functions by metal-assisted cleavage of the ATP gamma-phosphate, which is then in-line transferred to an acceptor phosphate to form polyP chains. Mutational analysis of the transmembrane domain indicates that VTC may integrate cytoplasmic polymer synthesis with polyP membrane translocation. Identification of the polyP-synthesizing enzyme opens the way to determine the functions of polyP in lower eukaryotes.

PubMed: 19390046
DOI: 10.1126/science.1168120

Experimental method

X-RAY DIFFRACTION (2.64 Å)