The CspA family in Escherichia coli : multiple gene duplication for stress adaptation

Abstract

SummaryCspA was originally found as the major cold-shock protein in Escherichia coli, consisting of 70-aminoacid residues. It forms a ␤-barrel structure with five anti-parallel ␤-strands and functions as an RNA chaperone. Its dramatic but transient induction upon cold shock is regulated at the level of transcription, mRNA stability and translation. Surprisingly, E. coli contains a large CspA family, consisting of nine genes from cspA to cspI. Phylogenetic analysis of these gene products and the cold-shock domain of human YB-1 protein reveals that there are two major branches in the evolution of CspA homologues: one branch for CspF and CspH, and another for all the other known CspA homologues from both prokaryotes and eukaryotes. The locations of these genes on the E. coli chromosome suggest that the large CspA family probably resulted from a number of gene duplications and, after subsequent adaptation, resulted in specific groups of genes that respond to different environmental stresses; for example, cspA, cspB and cspG for cold-shock stress and cspD for nutritional deprivation. The E. coli CspA family will be discussed in terms of their structures and functions, and their gene structures and regulation.

Conservation of the Cold Shock Domain Protein Family in Plants

“…structure (Yamanaka et al, 1998). As designated by red circles, these residues are almost completely conserved within all identified EST sequences (Fig.…”

“…Prokaryotic response to low temperature has been extensively studied in Escherichia coli and is accompanied by a spectacular accumulation of nucleic acidbinding CSPs (Graumann and Marahiel, 1998;Yamanaka et al, 1998;Bae et al, 2000). CspA, the most prominent of the nine-member E. coli CSP family, accumulates up to 10% of total proteins during cold stress (Jiang et al, 1997).…”

Independently recruited oxidases from the glucose-methanol-choline oxidoreductase family enabled chemical defences in leaf beetle larvae (subtribe Chrysomelina) to evolve

“…It has been suggested that these expansions of gene families may be correlated with the adaptation to different environmental issues or specific life strategies [48]. Because insects have evolved to occupy a vast diversity of habitats on the Earth, it can be hypothesized that these GMC genes have expanded further in insects in order to adapt to different environmental conditions.…”

Identification and regulation of cold-inducible factors of Bordetella bronchiseptica

“…Accordingly, it is assumed that the other members of the CSP family are involved in the protection against stresses other than low temperature; e.g. transcription of the cspD gene is responsive to nutrient deprivation (Yamanaka et al, 1998). The response to cold shock has been extensively studied in E. coli, where a specific set of 26-27 CIPs is induced under these conditions (Gualerzi et al, 2003).…”