African trypanosomiasis is a parasitic disease caused by specific class of protozoan organisms. The best-studied representative that group Trypanosoma brucei which transmitted tsetse flies and multiplies in the blood many mammals. Trypanosomes evade immune system altering their surface structure dominated layer variant glycoprotein (VSG). Although invariant proteins exist, they are inaccessible to humoral response. Using combinatorial selection method conjunction with live trypanosomes as...

We have isolated an unusual codon-specific translational suppressor in Escherichia coli. The resulted from a spontaneous mutation chromosomal gene during selection for suppressors of the auxotrophic nonsense trpA(UGA211). allows readthrough UGA mutations at two positions trpA and sites bacteriophage T4. It does not, however, suppress amber (UAG) or ochre (UAA) that were tested both genomes, some which same as suppressible mutations. also not allow mistranslation UGA-related missense UGG 211...

The majority of mitochondrial pre-mRNAs in kinetoplastid protozoa such as Trypanosoma, Leishmania, and Crithidia are substrates a posttranscriptional processing reaction referred to RNA editing. process results the insertion and, lesser extent, deletion uridylates, thereby completing informational content mRNAs. specificity editing is provided by guide RNAs (gRNAs), which serve templates for apparatus. In addition, relies on proteins, presumably acting within high-molecular-mass...

African trypanosomes are the causative agent of sleeping sickness. The therapeutics used to control and treat disease very ineffective thus, development improved drugs is urgently needed. Recently, new strategies for design novel trypanocidals have been put forward. Among them techniques that rely on parasite-specific RNA aptamers. One approach involves aptamer-directed transport lytic compounds lysosome parasite. aptamer has termed 2-16 here we report optimization its applications in vivo....

RNA-based devices controlling gene expression bear great promise for synthetic biology, as they offer many advantages such short response times and light metabolic burden compared to protein-circuits. However, little work has been done regarding their integration multilevel regulated circuits. In this work, we combined a variety of small transcriptional activator RNAs (STARs) toehold switches build highly effective AND-gates. To characterize the components dynamic range, used an Escherichia...

RNA editing in Trypanosoma brucei is a mitochondrial processing reaction that results the insertion and deletion of uridylate residues into otherwise untranslatable mRNAs. The process directed by guide RNAs which function to specify edited sequence. vitro requires protein extracts have been identified as part high molecular weight ribonucleoprotein complexes. Within complexes, are close contact with several proteins here we describe isolation cloning gRNA-interacting polypeptide from brucei....

Journal Article A ribosomal ambiguity mulation in the 530 loop of E.coli 16S rRNA Get access Michael O'Connor, O'Connor * *To whom correspondence should be addressed Search for other works by this author on: Oxford Academic PubMed Google Scholar H. Ulrich Göringer, Göringer 1Max-Planck Institute für Molekulare GenetikIhnestrasse 73, 1000 Berlin 33, Germany Albert E. Dahiberg Nucleic Acids Research, Volume 20, Issue 16, 25 August 1992, Pages 4221–4227, https://doi.org/10.1093/nar/20.16.4221...

ABSTRACT African trypanosomes cause sleeping sickness in humans and Nagana cattle. The parasites multiply the blood escape immune response of infected host by antigenic variation. Antigenic variation is characterized a periodic change parasite protein surface, which consists variant glycoprotein known as surface (VSG). Using SELEX (systematic evolution ligands exponential enrichment) approach, we report selection small, serum-stable RNAs, so-called aptamers, that bind to VSGs with...

RNA editing in kinetoplastids probably employs a macromolecular complex, the editosome, that is likely to include guide RNAs (gRNAs) which specify edited sequence. Specific ribonucleoprotein (RNP) complexes form vitro with gRNAs (H. U. Göringer, D. J. Koslowsky, T. H. Morales, and K. Stuart, Proc. Natl. Acad. Sci. USA, press) are potential editosomes or their precursors. We find several factors important for formation of these RNP identify specific gRNA-binding proteins present complexes....

Mitochondrial transcript maturation in African trypanosomes requires a U-nucleotide specific RNA editing reaction. In its most extreme form hundreds of U's are inserted into and deleted from primary transcripts to generate functional mRNAs. Unfortunately, both origin biological role the process have remained enigmatic. Here we report so far unrecognized structural feature pre-edited We demonstrate that cryptic pre-mRNAs contain numerous clustered G-nt, which fold G-quadruplex (GQ)...

RNA editing in Trypanosoma brucei mitochondria produces mature mRNAs by a series of enzyme-catalyzed reactions that specifically insert or delete uridylates association with macromolecular complex. Using mitochondrial fraction enriched for vitro activity, we produced several monoclonal antibodies are specific 21-kDa guide (gRNA) binding protein initially identified UV cross-linking. Immunofluorescence studies localize the to mitochondrion, preference kinetoplast. The cause supershift...

RNA editing in protozoan parasites is a mitochondrial processing reaction which exclusively uridylate residues are inserted into, and less frequently deleted from, pre-mRNAs. Molecules central to the process so-called guide RNAs (gRNAs) function as templates reaction. For detailed molecular understanding of mechanism knowledge structural features gRNAs will be essential. Here we report on computer-assisted modelling approach construct first three-dimensional gRNA model for gND7-506,...

Transcripts from mitochondrial (maxicircle) genes of kinetoplastid organisms undergo RNA editing characterized by a series reactions that insert and delete uridine nucleotides within the sequence pre-mRNAs. Guide RNAs, which complement fully edited mRNAs, provide information for an unknown mechanism. We report here guide molecules associate with other components to form four specific, stable ribonucleoprotein complexes. The complexes very rapidly at low monovalent cation concentration, their...

RNA editing is a mitochondrial transcript maturation process which evolved in kinetoplastid protozoa. It entails the insertion and deletion of exclusively uridine nucleotides directed by gRNAs into pre-mRNAs. Other participating components are not currently known. The aim this study was to identify proteins that direct physical contact with thereby possibly involved reaction. At low monovalent cation concentration (30 mM KCl) 8 polypeptides apparent molecular weights ranging from 124 9 kDa...

Trypanosomatids are single-cell eukaryotic parasites. Unlike higher eukaryotes, they control gene expression post-transcriptionally and not at the level of transcription initiation. This involves all known cellular RNA circuits, from mRNA processing to decay, translation, in addition a large panel RNA-interacting proteins that modulate abundance. However, other forms regulation, for example by lncRNAs, cannot be excluded. LncRNAs poorly studied trypanosomatids, with only single lncRNA...