Major cold shock protein of Escherichia coli

When exponentially growing Escherichia coli cell cultures were transferred from 37 degrees C to 10 degrees C or 15 degrees C, the production of a 7.4-kDa cytoplasmic protein (CS7.4) was prominently induced. The rate of CS7.4 production reached 13% of total protein synthesis within 1-1.5 hr after a shift to 10 degrees C and subsequently dropped to a lower basal level. Regulation of CS7.4 expression was very strict, such that synthesis of the protein was undetectable at 37 degrees C. We have cloned the gene encoding this protein and have completed the nucleotide sequence analysis, which revealed that the gene encodes a hydrophilic protein of 70 amino acid residues.