Universal nucleic acid-binding domain revealed by crystal structure of the B. subtilis major cold-shock protein.
The cold-shock response in both Escherichia coli and Bacillus subtilis is induced by an abrupt downshift in growth temperature. It leads to the increased production of the major cold-shock proteins, CS7.4 and CspB, respectively. CS7.4 is a transcriptional activator of two genes. CS7.4 and CspB share 43 per cent sequence identity with the nucleic acid-binding domain of the eukaryotic gene-regulatory Y-box factors. This cold-shock domain is conserved from bacteria to man and contains the RNA-binding RNP1 sequence motif. As a prototype of the cold-shock domain, the structure of CspB has been determined here from two crystal forms. In both, CspB is present as an antiparallel five-stranded beta-barrel. Three consecutive beta-strands, the central one containing the RNP1 motif, create a surface rich in aromatic and basic residues that are presumably involved in nucleic acid binding. Preferential binding of CspB to single-stranded DNA is observed in gel retardation experiments.
Schindelin
H
H
Institut für Kristallographie, Freie Universität Berlin, Germany.
Marahiel
M A
MA
Heinemann
U
U
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D001483:Base Sequence; D001665:Binding Sites; D003461:Crystallography; D004268:DNA-Binding Proteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016601:RNA-Binding Proteins / Q000737:chemistry*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D016601:RNA-Binding Proteins; C077188:cold-shock protein CspB, Bacteria