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Based on the genomic sequence data of Escherichia coli K-12 strain, we have constructed a complete set of cloned individual genes encoding Histidine-tagged proteins with or without GFP fused for functional genomic analysis. Each clone encodes a protein of predicted ORF attached by Histidines and seven spacer amino acids at the N-terminal end, and five spacer amino acids and GFP at the C-terminal end. SfiI restriction sites are generated at both the N- and C-terminal boundaries of ORF upon cloning, which enables easy transfer of ORF to other vector systems by cutting with SfiI. Expression of cloned ORF is under the control of an IPTG-inducible promoter, which is strictly repressed by lacIq repressor gene product. The set of cloned ORFs described here should provide unique resources for systematic functional genomic approaches including (i) construction of DNA microarray, (ii) production and purification of proteins, (iii) analysis of protein localization by monitoring GFP fluorescence and (iv) analysis of protein–protein interaction. [ABSTRACT FROM PUBLISHER]

Investigates the role of chaperones in the folding of fusion proteins from Escherichia coli. Production of fusion proteins with predicted molecular masses; Use of luciferases in biotechnology applications; Means of analyzing proteins.

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 σ70-dependent promoter activity presumably by forming a complex with σ70. To identify the region(s) of HscC responsible for growth inhibition and complex formation with σ70, 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 σ70-dependent promoter activity and form a complex with σ70. These results indicate that the ATPase domain of HscC rather than the substrate-binding domain is important for determining its functional specificity. [Copyright &y& Elsevier]