title: The novel NhaE-type Na(+)/H          (+) antiporter of the pathogenic bacterium Neisseria meningitidis.
abstract: Neisseria meningitidis is a pathogenic bacterium responsible for meningitis. The mechanisms underlying the control of Na(+) transmembrane movement, presumably important to pathogenicity, have been barely addressed. To elucidate the function of the components of the Na(+) transport system in N. meningitidis, an open reading frame from the genome of this bacterium displaying similarity with the NhaE type of Na(+)/H(+) antiporters was expressed in Escherichia coli and characterized for sodium transport ability. The N. meningitidis antiporter (NmNhaE) was able to complement an E. coli strain devoid of Na(+)/H(+) antiporters (KNabc) respecting the ability to grow in the presence of NaCl and LiCl. Ion transport assays in everted vesicles prepared from KNabc expressing NmNhaE from a plasmid confirmed its ability to translocate Na(+) and Li(+). Here is presented the characterization of the first NhaE from a pathogen, an important contribution to the comprehension of sodium ion metabolism in this kind of microorganisms.
authors.affiliation: BioTrop, Instituto de Investigação Científica Tropical, R. da Junqueira, 86, 1300-344 Lisboa, Portugal.
authors.forename: Pedro M F
authors.initials: PM
authors.lastname: Sousa
authors.forename: Marco A M
authors.initials: MA
authors.lastname: Videira
authors.forename: Thomas
authors.initials: T
authors.lastname: Vorburger
authors.forename: Sara T N
authors.initials: ST
authors.lastname: Silva
authors.forename: James W
authors.initials: JW
authors.lastname: Moir
authors.forename: Julia
authors.initials: J
authors.lastname: Steuber
authors.forename: Ana M P
authors.initials: AM
authors.lastname: Melo
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D018021:Lithium Chloride / Q000378:metabolism; D009345:Neisseria meningitidis / Q000235:genetics* / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D012965:Sodium Chloride / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics* / Q000378:metabolism
chemical_list: D017923:Sodium-Hydrogen Exchangers; D012965:Sodium Chloride; D018021:Lithium Chloride