Temperature mediated variation of DNA secondary structure in (A.T) clusters; evidence by use of the oligopeptide netropsin as a structural probe.

AUTOR(ES)

Reinert, K E

RESUMO

The titration viscometric investigation of the multi-mode interaction of netropsin (Nt) with (A.T) clusters of NaDNA12 and NH4DNA10 has been extended to different temperatures. The position of two boundaries on the r-scale (r= [Nt]bound/[DNA-P]) with increasing temperature steadily (rI/II) or more abruptly (rO/I) shifts to lower values. For the most (A.T) rich Nt-binding sites of modes (O), (I) and (II) this observation suggests the existence of an equilibrium between different DNA secondary structures with a different translation per base pair. The mode specific changes delta L1Nt of DNA contour length as induced by one Nt molecule proved to be almost independent of temperature. Concomitant stiffening effects increase with decreasing temperature, contrary to initial expectation. Conformational variability of (A.T) clusters may represent an essential feature in specific or selective DNA-protein interaction.

Documentos Relacionados

• Counterion dependent variation of DNA secondary structure in (A . T) clusters: evidence by use of netropsin as a structural probe.
• Probing of unusual DNA structures in topologically constrained form V DNA: use of restriction enzymes as structural probe.
• RFLP detected at the 8924 locus by a thyroglobulin cDNA probe.
• Aspects of specific protein-DNA interaction; multi-mode binding of the oligopeptide antibiotic netropsin to (A.T)-rich DNA segments.
• Detection of methicillin resistance in staphylococci by using a DNA probe.