[Construction of the genomic library of Halobacillus sp. D8 and isolation of the glycine betaine transporter betH gene].
Halobacillus sp. D8 is a sporing-forming, gram-positive moderately halophilic bacterium which could tolerate up to 25% (W/V) NaCl. A genomic library of Halobacillus sp. D8 was constructed using pUC18 as vector, and 9000 recombinant plasmids were obtained. By dot blot hybridization, colony PCR and DNA sequencing, the entire glycine betaine transporter betH gene was isolated from the constructed library. Inspection of the sequenced 4.3 kb DNA region revealed the presence of three ORFs. The putative ORF of betH is 1515bp long, encoding a 505-residue protein (BetH) with a calculated molecular mass of 56.1kD. Hydrophobicity plot analysis of BetH indicated a transmembrane protein containing 12 transmembrane regions. Homology searches for BetH of strain D8 in the GenBank using the BLAST program revealed significant sequence identities to other glycine betaine transporters: the putative glycine betaine transporter of O. iheyensis (64% identity), OpuD of B. subtilis (51% identity), BetH of H. trueperi (49% identity), BetL of L. monocytogenes (48% identity), BetM of M. halophilus (43% identity) and the putative glycine betaine transporter of B. halodurans (44% identity).
Key Laboratory for Agro-Microbial Resources and Application of Agriculture Ministry, College of Biological Sciences, China Agricultural University, Beijing 100094, China. luweidong2008@hotmail.com
Wei-dong
WD
Lu
Bai-suo
BS
Zhao
De-qin
DQ
Feng
Lei
L
Wang
Su-sheng
SS
Yang
D000595:Amino Acid Sequence; D001406:Bacillaceae / Q000235:genetics*; D001622:Betaine / Q000378:metabolism; D015723:Gene Library; D005798:Genes, Bacterial; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics*; D010957:Plasmids; D017386:Sequence Homology, Amino Acid
D026901:Membrane Transport Proteins; D001622:Betaine