title: NCgl2620 encodes a class II polyphosphate kinase in Corynebacterium glutamicum.
abstract: Corynebacterium glutamicum is able to accumulate up to 600 mM cytosolic phosphorus in the form of polyphosphate (poly P). Granular poly P (volutin) can make up to 37% of the internal cell volume. This bacterium lacks the classic enzyme of poly P synthesis, class I polyphosphate kinase (PPK1), but it possesses two genes, ppk2A (corresponds to NCgl0880) and ppk2B (corresponds to NCgl2620), for putative class II (PPK2) PPKs. Deletion of ppk2B decreased PPK activity and cellular poly P content, while overexpression of ppk2B increased both PPK activity and cellular poly P content. Neither deletion nor overexpression of ppk2A changed specific activity of PPK or cellular poly P content significantly. Purified PPK2B of C. glutamicum is active as a homotetramer and formed poly P with an average chain length of about 125, as determined with (31)P nuclear magnetic resonance. The catalytic efficiency of C. glutamicum PPK2B was higher in the poly P-forming direction than for nucleoside triphosphate formation from poly P. The ppk2B deletion mutant, which accumulated very little poly P and grew as C. glutamicum wild type under phosphate-sufficient conditions, showed a growth defect under phosphate-limiting conditions.
authors.affiliation: Institute of Molecular Microbiology and Biotechnology, Westfalian Wilhelms University Muenster, Correnstr. 3, Muenster, Germany.
authors.forename: Steffen N
authors.initials: SN
authors.lastname: Lindner
authors.forename: Dolores
authors.initials: D
authors.lastname: Vidaurre
authors.forename: Sabine
authors.initials: S
authors.lastname: Willbold
authors.forename: Siegfried M
authors.initials: SM
authors.lastname: Schoberth
authors.forename: Volker F
authors.initials: VF
authors.lastname: Wendisch
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D003470:Culture Media; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D011122:Polyphosphates / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D011122:Polyphosphates; D017856:Phosphotransferases (Phosphate Group Acceptor); C022424:polyphosphate kinase