many quality control mechanisms developed by cells to maintain the metabolic status quo. The cell’s objective in this case is to destroy mRNA species that contain premature termination codons (PTCs) so that only full-length proteins are produced. Targeted destruction of proteins that misfold as a result of missense mutations (those that result in substitution for amino acids in the protein) and...

We present an evolutionary hypothesis assuming that signals marking nucleotide synthesis (DNA replication and RNA transcription) evolved from multi- to unidimensional structures, and were carried over from transcription to translation. This evolutionary scenario presumes that signals combining secondary and primary nucleotide structures are evolutionary transitions. Mitochondrial replication in...

The imperfect fungus, Candida albicans is the major yeast pathogen in humans (1). We have analysed the codon usage in eleven C. albicans gene sequences reported in the EMBL and GenBank databases (Table). The codons are divided into three groups (low, medium and high) based upon their codon usage (Table), and these groups are compared with analogous groups for the highly expressed genes from S. ...

Expression of the murine leukemia virus pol gene occurs by translational readthrough of an in-frame UAG codon between the gag and pol coding regions. In a previous study, we mutated the UAG codon to UAA or UGA and demonstrated that both of these termination codons could be suppressed in reticulocyte lysates and in infected cells with the same efficiency as UAG. We now report the identity of the...

The mitochondrial genome is widely used for phylogenetic analyses and evolutionary biology. The complete mitochondrial genome of Thitarodes sejilaensis (Lepidoptera: Hepialidae) was sequenced and analyzed in this study. This mitogenome is a typical circular molecule of 15,290bp, with the gene content, orientation and order identical to other insects in the family Hepialidae. The genome nucleoti...

The complete sequence of the mitochondrial DNA (mtDNA) of the damsel bug, Alloeorhynchus bakeri, has been completed and annotated in this study. It represents the first sequenced mitochondrial genome of heteropteran family Nabidae. The circular genome is 15, 851 bp in length with an A+T content of 73.5%, contains the typical 37 genes that are arranged in the same order as that of the putative a...

Dominant mutations in the gene encoding the mRNA splicing factor PRPF31 cause retinitis pigmentosa, a hereditary form of retinal degeneration. Most of these mutations are characterized by DNA changes that lead to premature termination codons. We investigated 6 different PRPF31 mutations, represented by single-base substitutions or microdeletions, in cell lines derived from 9 patients with domin...

Pseudouridylation of messenger RNA emerges as an abundant modification involved in gene expression regulation. Pseudouridylation of stop codons in eukaryotic and bacterial cells results in stop-codon read through. The structural mechanism of this phenomenon is not known. Here we present a 3.1-Å crystal structure of Escherichia coli release factor 1 (RF1) bound to the 70S ribosome in response to...

The nonsense-mediated mRNA decay pathway functions to degrade aberrant mRNAs that contain premature translation termination codons. In Saccharomyces cerevisiae, the Upf1, Upf2, and Upf3 proteins have been identified as trans-acting factors involved in this pathway. Recent results have demonstrated that the Upf proteins may also be involved in maintaining the fidelity of several aspects of the t...

BACKGROUND Y14 is an RNA binding protein which is part of a multiprotein complex, the exon-exon junction complex (EJC), that assembles on the exon-exon junctions of mRNAs produced by splicing. The position-specific binding of Y14 persists on mRNAs after their export to the cytoplasm. Thus, Y14, together with its interacting proteins, has the capacity to communicate to the cytoplasm the processi...