Open AccessThe ATPase domain of HscC (DnaK homolog) is essential for interfering σ 70 activity in E. coli
Author(s) -
Arifuzzaman Mohammad,
Oshima Taku,
Mori Hirotada
Publication year - 2004
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00863-2
Subject(s) - atpase , escherichia coli , substrate (aquarium) , microbiology and biotechnology , chemistry , cell growth , biophysics , adenosine triphosphatase , cell , biology , biochemistry , enzyme , gene , ecology
HscC, a DnaK homolog in Escherichia coli , consists of adenosine triphosphatase (ATPase), substrate‐binding and C‐terminal domains. Overexpression of HscC markedly inhibits growth of host cell and reduces the σ 70 ‐dependent promoter activity presumably by forming a complex with σ 70 . To identify the region(s) of HscC responsible for growth inhibition and complex formation with σ 70 , domain swapping experiments were carried out between DnaK and HscC. Thus the chimeric proteins carrying the ATPase domain of HscC and substrate‐binding domains of either HscC or DnaK were found to inhibit the growth of the cell, reduce the σ 70 ‐dependent promoter activity and form a complex with σ 70 . These results indicate that the ATPase domain of HscC rather than the substrate‐binding domain is important for determining its functional specificity.