Structural redesign and stabilization of the overlapping tandem beta-turns of RNA polymerase II.
Int J Pept Protein Res
; 47(4): 260-8, 1996 Apr.
Article
en En
| MEDLINE
| ID: mdl-8738651
Peptides representing single repeat units of the carboxy-terminal domain (CTD) of RNA polymerase II (Tyr-Ser-Pro-Thr-Ser-Pro-Ser-Tyr-NH2, 1) contain overlapping Ser-Pro-Xaa-Xaa beta-turn forming sites which permit their overall structure to closely resemble members of the quinoxaline class of antitumor DNA bisintercalators. We have modified this native sequence at the i+2 positions of each beta-turn unit by substituting Gly or D-Ala in an attempt to preorganize this structure in aqueous solution. CD and NMR spectroscopic investigations confirmed the presence of type II beta-turns within each of the substituted peptides in contrast to the native sequence which contains a relatively low population of turn structure. In addition, an examination of singly substituted peptides suggests that an increase in the population of beta-turn structure within the amino-terminal Ser-Pro-Xaa-Xaa site also increased the formation of beta-turn structure in the carboxy-terminal (unmodified) Ser-Pro-Xaa-Xaa site; in comparison, substitution in the carboxy-terminal site did not influence structure in the remaining portion of the peptide. Overall, these results suggest that the structures formed could provide unique, preorganized linkers for the construction of novel DNA-interactive bisintercalators.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ARN Polimerasa II
Idioma:
En
Revista:
Int J Pept Protein Res
Año:
1996
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Dinamarca