title: Metagenomic cloning and characterization of Na⁺/H⁺ antiporter genes taken from sediments in Chaerhan Salt Lake in China.
abstract: A metagenomic library containing 8,000 clones was constructed by using genomic DNA obtained from Chaerhan Salt Lake in northwest China. Three Na(+)/H(+) antiporters, C4-NhaG, C47-NhaG and C49-NhaG that grouped to the NhaG family, were screened and cloned from this metagenome by complementing Escherichia coli strain KNabc (ΔnhaA ΔnhaB ΔchaA) in medium containing 0.2 M NaCl. The three putative Na(+)/H(+) antiporters were membrane proteins with 10, 11 and 11 transmembrane segments, respectively. They enabled E. coli KNabc to grow in medium containing 0.2-0.6 M Na(+) or 7-14 mM Li(+). Everted membrane vesicles prepared from E. coli KNabc cells carrying C49-NhaG exhibited Na(+)/H(+) and Li(+)/H(+) antiport activities.
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, People's Republic of China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Sanfeng
authors.initials: S
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D002681:China; D003001:Cloning, Molecular; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D005816:Genetic Complementation Test; D060106:Lakes / Q000382:microbiology*; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D054892:Metagenome; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D003470:Culture Media; D008565:Membrane Proteins; D017923:Sodium-Hydrogen Exchangers