The third zinc finger of TFIIIA stabilizes a hairpin structure of the non-coding strand in the internal control region of 5S RNA gene

Citation
T. Miura et al., The third zinc finger of TFIIIA stabilizes a hairpin structure of the non-coding strand in the internal control region of 5S RNA gene, J INORG BIO, 82(1-4), 2000, pp. 207-213
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics","Inorganic & Nuclear Chemistry
Journal title
JOURNAL OF INORGANIC BIOCHEMISTRY
ISSN journal
0162-0134 → ACNP
Volume
82
Issue
1-4
Year of publication
2000
Pages
207 - 213
Database
ISI
SICI code
0162-0134(200011)82:1-4<207:TTZFOT>2.0.ZU;2-J
Abstract
The structures of non-coding and coding strands in box C of the internal co ntrol region (ICR) of Xenopus laevis somatic 5S RNA gene have been examined by circular dichroism (CD) and Raman spectroscopy in the absence and prese nce of the third zinc finger of transcription factor IIIA (TFIIIA), which b inds to the ICR. The non-coding strand exhibits CD signals assignable to a hairpin and an unfolded structure. The presence of the hairpin structure is supported by Raman spectra, gel electrophoresis, and nucleotide deletion e xperiments. Binding of the zinc finger to the non-coding strand increases t he CD signal of hairpin structure, indicating stabilization of the hairpin structure by the zinc finger. In contrast, the corresponding coding strand remains unfolded even in the presence of the zinc finger. The TFIIIA-ICR co mplex is not only required for initiation of transcription but also lasts d uring many rounds of transcription of the 5S RNA gene including the ICR (Bo genhagen et al., Cell 28 (1982) 413). TFIIIA may play a role in promoting t he transcription by maintaining the unwound non-coding strand in the hairpi n structure and leaving the coding strand available for transcription by RN A polymerase. (C) 2000 Elsevier Science B.V. All rights reserved.