Transcription factor IIIA induced bending of the Xenopus somatic 5S gene promoter.

Abstract

Transcription factor IIIA (TFIIIA), the canonical zinc-finger protein, is a protein of relative molecular mass 39,000 (39K) that is required for transcription of 5S-ribosomal subunit genes in Xenopus. It binds in a sequence-specific manner to the internal control region of the 5S gene (see Fig. 1) and facilitates transcription of the gene by RNA polymerase III. It also binds to the 5S gene product to form a 7S ribonucleoprotein particle. In oocytes the 7S particle acts as a storage form of the RNA to be utilized later in development. TFIIIA binds to DNA through its 30 K N-terminal domain, which contains nine zinc-fingers. TFIIIA was the first protein described to have this type of DNA binding motif, but numerous other proteins have now been shown to have zinc-finger domains. A structure for a single zinc-finger from the yeast protein ADR1, was recently proposed based on two-dimensional NMR data (ref. 8), and a similar structure was proposed based on comparison with crystal structures of other metalloproteins. Although models for the interaction of TFIIIA with the 5S-ribosomal gene DNA have been proposed, based on nuclease digestion and methylation interference data, little precise structural information is available for TFIIIA and the physical basis for the interaction of zinc-fingers with DNA is not understood. Using both circular permutation and circularization assays we provide convincing biochemical evidence that TFIIIA bends the DNA at the internal promoter of the 5S gene.

• Authors: G P Schroth, G R Cook, E M Bradbury, J M Gottesfeld
• Journal: Nature (Nature) Vol. 340 Issue 6233 Pg. 487-8 (Aug 10 1989) ISSN: 0028-0836 [Print] ENGLAND
• PMID: 2755511 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• RNA, Ribosomal
• RNA, Ribosomal, 5S
• Transcription Factor TFIIIA
• Transcription Factors
• DNA

Topics

• Animals
• DNA (isolation & purification, metabolism)
• Kinetics
• Nucleic Acid Conformation
• Promoter Regions, Genetic
• RNA, Ribosomal (genetics)
• RNA, Ribosomal, 5S (genetics)
• Restriction Mapping
• Transcription Factor TFIIIA
• Transcription Factors (isolation & purification, metabolism)
• Xenopus