Recognition of T-rich single-stranded DNA by the cold shock protein Bs-CspB in solution.
Nucleic Acids Res
; 34(16): 4561-71, 2006.
Article
en En
| MEDLINE
| ID: mdl-16956971
ABSTRACT
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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Timidina
/
Bacillus subtilis
/
Proteínas Bacterianas
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ADN de Cadena Simple
Idioma:
En
Revista:
Nucleic Acids Res
Año:
2006
Tipo del documento:
Article
País de afiliación:
Alemania