Heat stable ssDNA/RNA-binding activity of a wheat cold shock domain protein

Abstract

Cold shock domain (CSD) proteins are distributed in bacteria, plant and animal. In E.coli, CSD proteins are highly induced after cold shock and function as a RNA chaperone. The cold-induced wheat WCSP1 protein belong to the CSD protein family. Here we demonstrated that purified recombinant WCSP1 is boiling soluble and binds ss/dsDNA and mRNA. Furthermore, boiled-WCSP1 retained its characteristic nucleic acid binding activity. A WCSP1 deletion mutant, containing only a CSD, lost ssDNA/RNA-binding activity; while a mutant containing the CSD and the first glycine-rich region (GR) displayed the activity. These date indicated that the first GR of WCSP1 is necessary for the binding activity but is not for the heat stability of the protein.