title: Cg2091 encodes a polyphosphate/ATP-dependent glucokinase of Corynebacterium glutamicum.
abstract: The Corynebacterium glutamicum gene cg2091 is encoding a polyphosphate (PolyP)/ATP-dependent glucokinase (PPGK). Previous work demonstrated the association of PPGK to PolyP granules. The deduced amino acid sequence of PPGK shows 45% sequence identity to PolyP/ATP glucomannokinase of Arthrobacter sp. strain KM and 50% sequence identity to PolyP glucokinase of Mycobacterium tuberculosis H37Rv. PPGK from C. glutamicum was purified from recombinant Escherichia coli. PolyP was highly preferred over ATP and other NTPs as substrate and with respect to the tested PolyPs differing in chain length; the protein was most active with PolyP(75). Gel filtration analysis revealed that PolyP supported the formation of homodimers of PPGK and that PPGK was active as a homodimer. A ppgK deletion mutant (Delta ppgK) showed slowed growth in minimal medium with maltose as sole carbon source. Moreover, in minimal medium containing 2 to 4% (w/v) glucose as carbon source, Delta ppgK grew to lower final biomass concentrations than the wild type. Under phosphate starvation conditions, growth of Delta ppgK was reduced, and growth of a ppgK overexpressing strain was increased as compared to wild type and empty vector control, respectively. Thus, under conditions of glucose excess, the presence of PPGK entailed a growth advantage.
authors.affiliation: Institute of Molecular Microbiology and Biotechnology, Westfalian Wilhelms University Münster, 48149, Münster, Germany.
authors.forename: Steffen N
authors.initials: SN
authors.lastname: Lindner
authors.forename: Sandra
authors.initials: S
authors.lastname: Knebel
authors.forename: Srinivas R
authors.initials: SR
authors.lastname: Pallerla
authors.forename: Siegfried M
authors.initials: SM
authors.lastname: Schoberth
authors.forename: Volker F
authors.initials: VF
authors.lastname: Wendisch
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001419:Bacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000737:chemistry / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D019281:Dimerization; D007700:Kinetics; D008969:Molecular Sequence Data; D010770:Phosphotransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D011122:Polyphosphates / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D011122:Polyphosphates; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; C024812:polyphosphate-glucose phosphotransferase