TY - JOUR
T1 - Effect of heterologous expression of molecular chaperone DnaK from Tetragenococcus halophilus on salinity adaptation of Escherichia coli
AU - Sugimoto, Shinya
AU - Nakayama, Jiro
AU - Fukuda, Daisuke
AU - Sonezaki, Shino
AU - Watanabe, Maki
AU - Tosukhowong, Amonlaya
AU - Sonomoto, Kenji
PY - 2003/1/1
Y1 - 2003/1/1
N2 - Molecular chaperone DnaK of halophilic Tetragenococcus halophilus JCM5888 was characterized under salinity conditions both in vitro and in vivo. The dnaK gene was cloned into an expression vector and transformed into Escherichia coli. The DnaK protein obtained from the recombinant E. coli showed a significantly higher refolding activity of denatured lactate dehydrogenase than that from non-halophilic Lactococcus lactis under NaCl concentrations higher than 1 M. E. coil without the overexpression of DnaK exhibited a growth profile with a prolonged lag phase and suppressed maximum cell density in Luria-Bertani medium containing 5% (0.86 M) NaCl. On the contrary, the overexpression of T. halophilus DnaK greatly shortened this prolonged lag phase with no effect on maximum growth, while that of L. lactis DnaK decreased maximum growth. The amount of protein aggregates was increased by salt stress in the E. coli cells, while this aggregation was greatly suppressed by the overexpression of T. halophilus DnaK. These results suggest that heterologous overexpression of T. halophilus DnaK, via its chaperone activity, promotes salinity adaptation of E. coli.
AB - Molecular chaperone DnaK of halophilic Tetragenococcus halophilus JCM5888 was characterized under salinity conditions both in vitro and in vivo. The dnaK gene was cloned into an expression vector and transformed into Escherichia coli. The DnaK protein obtained from the recombinant E. coli showed a significantly higher refolding activity of denatured lactate dehydrogenase than that from non-halophilic Lactococcus lactis under NaCl concentrations higher than 1 M. E. coil without the overexpression of DnaK exhibited a growth profile with a prolonged lag phase and suppressed maximum cell density in Luria-Bertani medium containing 5% (0.86 M) NaCl. On the contrary, the overexpression of T. halophilus DnaK greatly shortened this prolonged lag phase with no effect on maximum growth, while that of L. lactis DnaK decreased maximum growth. The amount of protein aggregates was increased by salt stress in the E. coli cells, while this aggregation was greatly suppressed by the overexpression of T. halophilus DnaK. These results suggest that heterologous overexpression of T. halophilus DnaK, via its chaperone activity, promotes salinity adaptation of E. coli.
UR - http://www.scopus.com/inward/record.url?scp=0041375301&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0041375301&partnerID=8YFLogxK
U2 - 10.1016/S1389-1723(03)90114-9
DO - 10.1016/S1389-1723(03)90114-9
M3 - Article
C2 - 16233497
AN - SCOPUS:0041375301
VL - 96
SP - 129
EP - 133
JO - Journal of Bioscience and Bioengineering
JF - Journal of Bioscience and Bioengineering
SN - 1389-1723
IS - 2
ER -