Cloning and characterization of two guide RNA-binding proteins from mitochondria of Crithidia fasciculata: gBP27, a novel protein, and gBP29, the orthologue of Trypanosoma brucei gBP21.

In kinetoplastid protozoa, mitochondrial (mt) mRNAs are post-transcriptionally edited by insertion and deletion of uridylate residues, the information being provided by guide (g)RNAs. Currently popular mechanisms for the editing process envisage a series of consecutive 'cut-and-paste' reactions, carried out by a complex RNP machinery. Here we report on the purification, cloning and functional analysis of two gRNA-binding proteins of 28.

Functional analysis of chimeras derived from the Sinorhizobium meliloti and Mesorhizobium loti nodC genes identifies regions controlling chitin oligosaccharide chain length.

The rhizobial nodulation gene nodC encodes an N-acetylglucosaminyltransferase that is responsible for the synthesis of chitin oligosaccharides. These oligosaccharides are precursors for the synthesis of the lipo-chitin oligosaccharides that induce cell division and differentiation during the development of nitrogen-fixing root nodules in leguminous plants. The NodC proteins of Mesorhizobium loti and Sinorizobium meliloti yield chitinpentaose and chitintetraose as their main products, respectively.

Computing with DNA by operating on plasmids.

A new method of computing using DNA plasmids is introduced and the potential advantages are listed. The new method is illustrated by reporting a laboratory computation of an instance of the NP-complete algorithmic problem of computing the cardinal number of a maximal independent subset of the vertex set of a graph. A circular DNA plasmid, specifically designed for this method of molecular computing, was constructed.

Further evidence for the presence of mitochondrially encoded subunits in cytochrome c oxidase of the trypanosomatid Crithidia fasciculata.

Mitochondrial mRNAs in trypanosomatids are edited by uridylate insertion and deletion. The respiratory chain complexes cytochrome c reductase, cytochrome c oxidase and F0F1-ATPase of the insect trypanosomatid Crithidia fasciculata have been isolated and analysed by peptide microsequencing, but so far, proteins encoded by edited (and unedited) mitochondrial mRNAs have not been found. In this paper, we provide evidence that the mitochondrial mRNAs encoding the three large subunits of cytochrome c oxidase are indeed translated.

Characterization of the respiratory chain from cultured Crithidia fasciculata.

Mitochondrial mRNAs encoding subunits of respiratory-chain complexes in kinetoplastids are post-transcriptionally edited by uridine insertion and deletion. In order to identify the proteins encoded by these mRNAs, we have analyzed respiratory-chain complexes from cultured cells of Crithidia fasciculata with the aid of 2D polyacrylamide gel electrophoresis (PAGE). The subunit composition of F0F1-ATPase (complex V), identified on the basis of its activity as an oligomycin-sensitive ATPase, is similar to that of bovine mitochondrial F0F1-ATPase.