3G3O: Crystal structure of the cytoplasmic tunnel domain in yeast Vtc2p

Citation:
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.
PDB ID: 3G3ODownload
MMDB ID: 72474
PDB Deposition Date: 2009/2/2
Updated in MMDB: 2018/06
Experimental Method:
x-ray diffraction
Resolution: 2.1  Å
Source Organism:
Similar Structures:
Biological Unit for 3G3O: monomeric; determined by author and by software (PISA)
Molecular Components in 3G3O
Label Count Molecule
Protein (1 molecule)
1
Vacuolar Transporter Chaperone 2(Gene symbol: VTC2)
Molecule annotation
Chemicals (3 molecules)
1
3
* Click molecule labels to explore molecular sequence information.

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