Conserved Site

Cold-shock conserved site (IPR019844)

Short name: Cold-shock_CS

Description

When Escherichia coli is exposed to a temperature drop from 37 to 10 degrees centigrade, a 4-5 hour lag phase occurs, after which growth is resumed at a reduced rate [PMID: 1912512]. During the lag phase, the expression of around 13 proteins, which contain specific DNA-binding regions [PMID: 2247479], is increased 2-10 fold. These so-called 'cold shock' proteins (CSPs) are thought to help the cell to survive in temperatures lower than optimum growth temperature, by contrast with heat shock proteins, which help the cell to survive in temperatures greater than the optimum, possibly by condensation of the chromosome and organisation of the prokaryotic nucleoid [PMID: 1912512]. A conserved domain of about 70 amino acids has been found in prokaryotic and eukaryotic DNA-binding proteins [PMID: 1622933, PMID: 2184368, PMID: 8022259]. This domain is known as the 'cold-shock domain' (CSD), part of which is highly similar [PMID: 1614871] to the RNP-1 RNA-binding motif.

CSPs include the major cold-shock proteins CspA and CspB in bacteria and the eukaryotic gene regulatory factor Y-box protein. CSP expression is up-regulated by an abrupt drop in growth temperature. CSPs are also expressed under normal condition at lower level. The function of cold-shock proteins is not fully understood. They preferentially bind poly-pyrimidine region of single-stranded RNA and DNA [PMID: 8321288]. CSPs are thought to bind mRNA and regulate ribosomal translation, mRNA degradation, and the rate of transcription termination. The human Y-box protein, which contains a CSD [PMID: 11851341], regulates transcription and translation of genes that contain the Y-box sequence in their promoters. This specific ssDNA-binding properties of CSD are required for the binding of Y-box protein to the promoter's Y-box sequence, thereby regulating transcription.

This conserved region is located at the N-terminal. The beginning of this region is highly similar to the RNP-1 RNA-binding motif [PMID: 1614871].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns