title: Overproduction of YjbB reduces the level of polyphosphate in Escherichia coli: a hypothetical role of YjbB in phosphate export and polyphosphate accumulation.
abstract: Intracellular phosphate (P(i) ) is normally maintained at a fairly constant concentration in Escherichia coli, mainly by P(i) transport systems and by the 'phosphate balance' between P(i) and polyphosphate (polyP). We have reported previously that excess uptake of P(i) in a phoU mutant results in elevated levels of polyP. Here, we found that the elevated levels of polyP in the mutant could be reduced by the overproduction of YjbB, whose N-terminal half contains Na(+) /P(i) cotransporter domains. The rate of P(i) export increased when the YjbB overproducer grew on a medium containing glycerol-3-phosphate. These results strongly suggested that YjbB reduced the elevated levels of polyP in the phoU mutant by exporting intracellular excess P(i) .
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Motomura
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Hirota
authors.forename: Nobuteru
authors.initials: N
authors.lastname: Ohnaka
authors.forename: Mai
authors.initials: M
authors.lastname: Okada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ikeda
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Morohoshi
authors.forename: Hisao
authors.initials: H
authors.lastname: Ohtake
authors.forename: Akio
authors.initials: A
authors.lastname: Kuroda
mesh_terms: D000123:Acetyltransferases / Q000235:genetics* / Q000378:metabolism*; D001692:Biological Transport; D015536:Down-Regulation; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D010710:Phosphates / Q000378:metabolism*; D011122:Polyphosphates / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D010710:Phosphates; D011122:Polyphosphates; D000123:Acetyltransferases