2f52

Publication Abstract from PubMed

Cold shock proteins (CSP) belong to the family of single-stranded nucleic acid binding proteins with OB-fold. CSP are believed to function as 'RNA chaperones' and during anti-termination. We determined the solution structure of Bs-CspB bound to the single-stranded DNA (ssDNA) fragment heptathymidine (dT7) by NMR spectroscopy. Bs-CspB reveals an almost invariant conformation when bound to dT7 with only minor reorientations in loop beta1-beta2 and beta3-beta4 and of few aromatic side chains involved in base stacking. Binding studies of protein variants and mutated ssDNA demonstrated that Bs-CspB associates with ssDNA at almost diffusion controlled rates and low sequence specificity consistent with its biological function. A variation of the ssDNA affinity is accomplished solely by changes of the dissociation rate. 15N NMR relaxation and H/D exchange experiments revealed that binding of dT7 increases the stability of Bs-CspB and reduces the sub-nanosecond dynamics of the entire protein and especially of loop beta3-beta4.

Recognition of T-rich single-stranded DNA by the cold shock protein Bs-CspB in solution.,Zeeb M, Max KE, Weininger U, Low C, Sticht H, Balbach J Nucleic Acids Res. 2006;34(16):4561-71. Epub 2006 Sep 6. PMID:16956971^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.