Structure in solution of the major cold-shock protein from Bacillus subtilis

Abstract

The cold-shock domain (CSD) is found in many eukaryotic transcriptional factors and is responsible for the specific binding to DNA of a cis-element called the Y-box. The same domain exists in the sequence of the Xenopus RNA-binding proteins FRG Y1 and FRG Y2 (refs 1, 3). The major cold-shock proteins of Escherichia coli (CS7.4) and B. subtilis (CspB) have sequences that are more than 40 per cent identical to the cold-shock domain. We present here the three-dimensional structure of CspB determined by nuclear magnetic resonance spectroscopy. The 67-residue protein consists of an antiparallel five-stranded beta-barrel with strands connected by turns and loops. The structure resembles that of staphylococcal nuclease and the gene-5 single-stranded-DNA-binding protein. A three-stranded beta-sheet, which contains the conserved RNA-binding motif RNP1 as well as a motif similar to RNP2 in two neighbouring antiparallel beta-strands, has basic and aromatic residues at its surface which could serve as a binding site for single-stranded DNA. CspB binds to single-stranded DNA in gel retardation experiments.

A family of cold shock proteins in Bacillus subtilis is essential for cellular growth and for efficient protein synthesis at optimal and low temperatures

“…7 and in Graumann and Marahiel (1994). RNA was labelled with [␥-32 P]-dATP using T4 polynucleotide kinase as described in Schnuchel et al (1993).…”

RNA remodeling and gene regulation by cold shock proteins

“…The three-dimensional structures of CspA from E. coli and CspB from B. subtilis have been resolved by X-ray crystallography and NMR-analysis and found to be very similar. [69][70][71][72][73] The protein consists of five antiparallel β-strands (β1 to β5) that form a β-barrel structure with two β-sheets. Two RNAbinding motifs, RNP1 and RNP2, are located on the β2 and β3 strands, respectively.…”

Comparison of structure, function and regulation of plant cold shock domain proteins to bacterial and animal cold shock domain proteins

“…Among bacterial Csps and YB-1, the ~70 residues that comprise the CSD represent the only region that exhibits a high level of sequence conservation. Studies on the CSD of YB-1 revealed a β-barrel spatial structure bearing similarity to bacterial Csps with a similar arrangement of RNA binding motifs (5,10,13). The C-terminal auxiliary domain was proposed to have a nonspecific affinity for RNA and DNA which may result from its interaction with negatively charged phosphate groups of nucleic acids (14).…”

“…CspB from Bacillus subtilis and CspD from E. coli purify as dimers in solution. In the case of B. subtilis CspB, dimers are formed between two anti-parallel CspB molecules through interactions between the β4-β4 and β4-N terminus (5,10). On the other hand, CspA from E. coli was crystallized as a monomer (6,7).…”