The cold-shock response in bacteria

The 'cold shock' response that occurs when exponentially growing Escherichia coli at 37 degrees C are transferred to 10 degrees C leads to the cesation of most protein synthesis, however, about 14 'cold shock' proteins continue to be made. These 'cold shock' proteins facilitate growth at low temperatures. Central to the regulation of this switch in gene expression is the 200 fold induction in the relative rate of synthesis of a small cold-shock protein only 70 amino acids in length, known as CS7.4. There is a remarkable conservation through evolution of the primary sequence found in this small cold shock protein and that of a nucleic acid binding domain within the Y-box family of eukaryotic gene regulatory proteins. Parallel studies on CS7.4 and the Y-box proteins have elucidated both molecular mechanisms regulating the cold shock response and a novel site for the regulation of eukaryotic gene expression.