Streptomyces contain a 7.0 kDa cold shock like protein. Nucleic Acids Res

The major protein synthesized in Escherichia coli following a shift of exponentially growing cells from 37 to 10°C is a 7.4 kDa hydrophilic protein, CS7.4 (1). Recent studies indicate that CS7.4 may be a positive transcriptional regulator for genes belonging to the cold shock regulon (2, 3). Remarkably, CS7.4 has extensive sequence similarity to the DNA binding domain of a family of eucaryotic nucleic acid binding proteins, the Y box transcription factors (4). It has been proposed that the common DNA recognition motif, the cold shock domain (CSD), present in these procaryotic and eucaryotic proteins is of ancient origin and widespread (5). We report here the amino acid sequence of a 7.0 kDa protein from the gram positive bacterium Streptomyces clavuligerns that closely resembles that of the E.coli CS7.4 protein. During a study of the thioredoxin system of S.clavulugerus we noticed tha