Characterization of the ves gene, which is expressed at a low temperature in Escherichia coli

A gene, designated ves, that is expressionally responsive to temperature was found in Escherichia coli. Experiments with a single-copy lacZ operon fusion and primer extension analysis revealed that ves was expressed at a low temperature with a peak around 25 degrees C but was hardly expressed at 42 degrees C. After a temperature downshift, the mRNA level increased until 6 to 12 h and then decreased. Consistently, an A + T-rich sequence similar to UP elements seen in cold-shock inducible cold-shock protein (Csp) genes was found up-stream of the ves promoter, and its 5'-untranslated region was found to share similarity with those of the cold-shock inducible and cold-adaptive cspA and cspB genes. Additionally, a putative down-stream box, which also exists in cold-inducible proteins, was found. The ves product was identified by overproduction and determination of its N-terminal sequence. Similarity of the C-terminal portion of Ves to the CspA family suggests that Ves belongs to this family. The results of gene-disruption experiments suggest that ves is not essential for E. coli.