3PF4: Crystal Structure Of Bs-Cspb In Complex With R(Gucuuua)

Bacterial cold shock proteins (CSPs) regulate the cellular response to temperature downshift. Their general principle of function involves RNA chaperoning and transcriptional antitermination. Here we present two crystal structures of cold shock protein B from Bacillus subtilis (Bs-CspB) in complex with either a hexanucleotide (5'-UUUUUU-3') or heptanucleotide (5'-GUCUUUA-3') single-stranded RNA (ssRNA). Hydrogen bonds and stacking interactions between RNA bases and aromatic sidechains characterize individual binding subsites. Additional binding subsites which are not occupied by the ligand in the crystal structure were revealed by NMR spectroscopy in solution on Bs-CspB.RNA complexes. Binding studies demonstrate that Bs-CspB associates with ssDNA as well as ssRNA with moderate sequence specificity. Varying affinities of oligonucleotides are reflected mainly in changes of the dissociation rates. The generally lower binding affinity of ssRNA compared to its ssDNA analog is attributed solely to the substitution of thymine by uracil bases in RNA.
PDB ID: 3PF4Download
MMDB ID: 93688
PDB Deposition Date: 2010/10/27
Updated in MMDB: 2011/12
Experimental Method:
x-ray diffraction
Resolution: 1.38  Å
Source Organism:
synthetic construct
Similar Structures:
Biological Unit for 3PF4: monomeric; determined by author and by software (PISA)
Molecular Components in 3PF4
Label Count Molecule
Protein (1 molecule)
Cold Shock Protein Cspb(Gene symbol: cspB)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB