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From Proteopedia
Crystal Structure of Escherichia coli Polyphosphate Kinase
Structural highlights
FunctionPPK1_ECOLI Catalyzes the reversible transfer of the terminal phosphate of ATP to form a long-chain polyphosphate (polyP). Can form linear polymers of orthophosphate with chain lengths up to 1000 or more. Can use GTP instead of ATP, but the efficiency of GTP is 5% that of ATP. Also exhibits several other enzymatic activities, which include: ATP synthesis from polyP in the presence of excess ADP, general nucleoside-diphosphate kinase activity, linear guanosine 5'-tetraphosphate (ppppG) synthesis and autophosphorylation.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPolyphosphate (polyP), a linear polymer of hundreds of orthophosphate residues, exists in all tested cells in nature, from pathogenic bacteria to mammals. In bacteria, polyP has a crucial role in stress responses and stationary-phase survival. Polyphosphate kinase (PPK) is the principal enzyme that catalyses the synthesis of polyP in bacteria. It has been shown that PPK is required for bacterial motility, biofilm formation and the production of virulence factors. PPK inhibitors may thus provide a unique therapeutic opportunity against antibiotic-resistant pathogens. Here, we report crystal structures of full-length Escherichia coli PPK and its complex with AMPPNP (beta-gamma-imidoadenosine 5-phosphate). PPK forms an interlocked dimer, with each 80 kDa monomer containing four structural domains. The PPK active site is located in a tunnel, which contains a unique ATP-binding pocket and may accommodate the translocation of synthesized polyP. The PPK structure has laid the foundation for understanding the initiation of polyP synthesis by PPK. Crystal structure of a polyphosphate kinase and its implications for polyphosphate synthesis.,Zhu Y, Huang W, Lee SS, Xu W EMBO Rep. 2005 Jul;6(7):681-7. PMID:15947782[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Escherichia coli | Large Structures | Huang W | Lee SS | Xu W | Zhu Y
