When <taxon tax_id="562">Escherichia coli</taxon> is exposed to a temperature drop from 37 to 10 degreescentigrade, a 4-5 hour lag phase occurs, after which growth is resumed ata reduced rate [<cite idref="PUB00004548"/>]. During the lag phase, the expression of around 13proteins, which contain specific DNA-binding regions [<cite idref="PUB00004718"/>], is increased2-10 fold. These so-called 'cold shock' proteins are thought to help thecell to survive in temperatures lower than optimum growth temperature, bycontrast with heat shock proteins, which help the cell to survive intemperatures greater than the optimum, possibly by condensation of thechromosome and organisation of the prokaryotic nucleoid [<cite idref="PUB00004548"/>].A conserved domain of about 70 amino acids has been found in prokaryotic andeukaryotic DNA-binding proteins [<cite idref="PUB00004326"/>, <cite idref="PUB00004061"/>, <cite idref="PUB00003861"/>]. This domain is known as the'cold-shock domain' (CSD), part of which is highly similar [<cite idref="PUB00004406"/>] to the RNP-1 RNA-binding motif.<p>This conserved region is located at the N-terminal. The beginning of this region is highly similar to the RNP-1 RNA-binding motif [<cite idref="PUB00004406"/>].</p> Cold-shock conserved site