2f52
From Proteopedia
Solution structure of cold shock protein CspB from Bacillus subtilis in complex with heptathymidine
Structural highlights
FunctionCSPB_BACSU Binds to the pentamer sequences ATTGG and CCAAT with highest affinity in single-stranded DNA, and also to other sequences. Has greater affinity for ATTGG than CCAAT. Can act as transcriptional activator of cold shock genes by recognizing putative ATTGG-box elements present in promoter regions of genes induced under cold shock conditions. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCold 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. References
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