A novel NhaD-type Na+/H+antiporter from the moderate halophile and alkaliphile Halomonas alkaliphila.
In this study, a NhaD-type Na+/H+antiporter gene designated Ha-nhaD was obtained by selection of genomic DNA from the moderate halophile and alkaliphile Halomonas alkaliphila in Escherichia coli KNabc lacking 3 major Na+/H+antiporters. The presence of Ha-NhaD conferred tolerance of E. coli KNabc to NaCl up to 0.6 mol·L-1and to LiCl up to 0.2 mol·L-1and to an alkaline pH. pH-dependent Na+(Li+)/H+antiport activity was detected from everted membrane vesicles prepared from E. coli KNabc/pUC-nhaD but not those of KNabc/pUC18. Ha-NhaD exhibited Na+(Li+)/H+antiport activity over a wide pH range from 7.0 to 9.5, with the highest activity at pH 9.0. Protein sequence alignment and phylogenetic analysis revealed that Ha-NhaD is significantly different from the 7 known NhaD-type Na+/H+antiporters, including Dw-NhaD, Dl-NhaD, Vp-NhaD, Vc-NhaD, Aa-NhaD, He-NhaD, and Ha-NhaD1. Although Ha-NhaD showed a closer phylogenetic relationship with Ha-NhaD2, a significant difference in pH-dependent activity profile exists between Ha-NhaD and Ha-NhaD2. Taken together, Ha-nhaD encodes a novel pH-dependent NhaD-type Na+/H+antiporter.
a Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, 150030, People's Republic of China.|b College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163319, People's Republic of China.
Yanhong
Y
Wang
a Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
Na
N
Song
a Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
Lina
L
Yang
a Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, 150030, People's Republic of China.|c Department of Microbiology, Soils, Water & Environment Research Institute, Agriculture Research Center, Egypt.
Heba
H
Abdel-Motaal
a Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
Rui
R
Zhang
a Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
Zhenglai
Z
Zhang
a Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
Fankui
F
Meng
a Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
Juquan
J
Jiang
D000468:Alkalies; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D020632:Halomonas / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D055051:Salt-Tolerant Plants; D012965:Sodium Chloride / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*
D000468:Alkalies; D001426:Bacterial Proteins; D017923:Sodium-Hydrogen Exchangers; D012965:Sodium Chloride
Halomonas alkaliphila; Na+/H+ antiporter; NhaD; antiport Na+/H+; halophile et alcaliphile modéré; moderate halophile and alkaliphile; pH-dependent activity profile; profil d’activités dépendantes du pH