Disease relevance of LOC397777

• Bulged bases in RNA helices are potentially significant in RNA folding and in providing sites for specific protein-RNA interactions, as illustrated by TFIIIA of Xenopus and the coat protein of phage R17 [1].
• Novobiocin and coumermycin, inhibitors of the B subunit of Escherichia coli DNA gyrase, inhibit the binding of Xenopus transcription factor IIIA (TFIIIA) to the 5 S RNA gene [2].

High impact information on LOC397777

• Taken together, our findings suggest that RNA and DNA binding are overlapping, though separable functions of the nine zinc finger elements in TFIIIA, occurring via fundamentally different molecular mechanisms [3].
• The secondary/tertiary structure of the central domain in 5S RNA, not its primary sequence, is found to carry the essential structural information for TFIIIA binding in Xenopus oocytes [3].
• In addition, we show that RNP migration depletes the nucleus of TFIIIA, resulting in a loss of transcription competence for newly injected 5S rRNA genes [4].
• Thus, L5 and TFIIIA define a new functional class of proteins involved in the nuclear export of RNA [4].
• The concentration of the trans-acting factor, TFIIIA, required for the activation of 5S RNA genes in Xenopus can be elevated in developing embryos by injecting a synthetic full-length mRNA into fertilized eggs [5].

Chemical compound and disease context of LOC397777

• Zn-TFIIIA was purified from E. coli containing the cloned sequence for Xenopus laevis oocyte TFIIIA and its stoichiometry of bound Zn(2+) was shown to depend on the details of the isolation process [6].

Biological context of LOC397777

• To obtain insights into the mechanism by which TFIIIA recognizes 5 S RNA, we determined the solution structure of the middle three zinc fingers bound to the central core of 5 S RNA [7].
• Transcription factor IIIA (TFIIIA) is a Cys2His2 zinc finger protein that regulates expression of the 5 S ribosomal RNA gene by binding specifically to the internal control element [7].
• The levels of both 5S RNA and TFIIIA are regulated throughout oogenesis and embryonic development [8].
• We report sequence homologies between TFIIIA cDNA and regulatory regions of the Xenopus tmet and 5S RNA genes [8].
• Using the cDNA clone, we have determined that there is (are) one or a small number of TFIIIA gene(s) per Xenopus haploid genome, and we have estimated the size and levels of TFIIIA RNA throughout Xenopus development [8].

Anatomical context of LOC397777

• Initiation of 5S RNA gene transcription in Xenopus oocytes requires a 38,500 dalton polypeptide, TFIIIA [8].
• Tissue culture cells and mature erythrocytes have equivalent numbers of somatic 5S RNA genes programmed into transcription complexes, yet the former cell type has a greater than 50-fold higher cellular content of transcription factor IIIA (TFIIIA) [9].
• Functional transcription complexes on somatic 5S RNA genes in nucleated erythrocytes of Xenopus are stable for weeks, perhaps months, even though a mature erythrocyte has less than two molecules of TFIIIA for each somatic 5S RNA gene [9].
• The importance of ICR III and ICR IV in transcription initiation and in sequestering transcription factors suggests the presence of an activity in D. melanogaster similar to transcription factor TFIIIA of Xenopus laevis and HeLa cells [10].
• Seven stable hybridoma lines were established and shown to secrete antibodies directed against different antigenic structures present on distinct peptides of the factor (generated by cleavage of TFIIIA with cyanogen bromide) [11].

Associations of LOC397777 with chemical compounds

• The chromatin assembled with TFIIIA is dynamic and rapidly relaxed by novobiocin; the chromatin assembled without TFIIIA is static and unaffected by novobiocin [12].
• Here, we report the results of an EXAFS (extended X-ray absorption fine structure) study of TFIIIA which shows that the coordination sphere of the zinc sites consists of two cysteine and two histidine residues [13].
• The crystal structure of the six NH2-terminal zinc fingers of Xenopus laevis transcription factor IIIA (TFIIIA) bound with 31 bp of the 5S rRNA gene promoter has been determined at 3.1 A resolution [14].
• In order to investigate the molecular basis of how TFIIIA binds to the nucleosome and to ascertain if binding involves all nine zinc fingers and/or displacement of histone-DNA interactions, we examined the TFIIIA-nucleosome complex by hydroxyl radical footprinting and site-directed protein-DNA cross-linking [15].
• We tested the ability of altered 5S RNAs to bind TFIIIA, taking advantage of the slower mobility of 7S particles compared with free 5S RNA in native polyacrylamide gels [16].

Physical interactions of LOC397777

• Results presented in three recent articles 1-3 together demonstrate that replacement of the cleavage stage linker histone B4 by somatic H1 leads to chromatosomes positioned directly over these genes and adjacent sequences so as to occlude the binding site for the critical transcription factor TFIIIA [17].

Regulatory relationships of LOC397777

• These studies suggest that TFIIIA may stimulate DNA supercoiling by enhancing the development of protein-DNA interactions via a mechanism that may include nucleosome assembly [18].

Other interactions of LOC397777

• Thus, the role of FRGY2 in the transcription and storage of maternal mRNA is similar to that of the transcription factor TFIIIA in the transcription and storage of 5S rRNA from the oocyte type 5S rRNA genes [19].
• Although considerable sequence variation exists in these TFIIIA zinc fingers, the Cys/His, Tyr/Phe and Leu residues are strictly conserved between X. laevis and X. borealis [20].

Analytical, diagnostic and therapeutic context of LOC397777

• We report here that the circular dichroism (CD) spectrum of a synthetic 54-bp deoxyoligonucleotide corresponding to the TFIIIA binding site is similar to the CD spectrum of B-form DNA in solution [21].
• Immunoblotting experiments with polyclonal and monoclonal anti-transcription factor IIIA (TFIIIA) antibodies reveal different electrophoretic forms of TFIIIA in extracts from immature and mature oocytes of Xenopus laevis [22].
• By gel shift analysis, chemical footprinting, methylation intereference, and point mutation analysis, we demonstrate that the TFIIIA distal element factor and major late transcription factor have similar DNA-binding properties [23].
• Electron microscopy reveals that transcription factor TFIIIA bends 5S DNA [24].
• Nine separate TFIIIA mutants were expressed in Xenopus embryos following microinjection of their respective in vitro-derived mRNAs [25].

References