Search results for "Intron"
showing 10 items of 420 documents
The human complement C9 gene: structural analysis of the 5′ gene region and genetic polymorphism studies
2001
Summary C9 is the last of the human complement components creating the membrane attack complex. The single chain serum protein is encoded by a gene located on chromosome 5p13 that is composed of 11 exons. With the aid of inverse PCR, the hitherto unknown regions flanking exon 1 and the 3′ part of exon 11 (3′UTR) have been sequenced. A computer-based analysis of the 300-bp region located just upstream of the AUG start codon showed homologies to known DNA modules which affect the transcriptional regulation of certain genes. The most striking of these is a sequence that may substitute the missing TATA box in initiating C9 transcription. In the 3′UTR, three successive polyadenylation signals we…
Analysis of the Single-Nucleotide Polymorphism in the 5′UTR and Part of Intron I of the Sheep MSTN Gene
2011
The myostatin (MSTN) gene region encompassing the 5′UTR and part of intron I was sequenced in animals of two herds of Latvian Darkhead sheep to extend data on the ovine MSTN gene polymorphism and to provide information useful for local breed conservation. Two and four polymorphic loci were revealed in the 5′UTR and intron I. Four and five local haplotypes were constructed, respectively. The genotyping data obtained and that previously reported for the same genomic region were combined in one dataset for the haplotype analysis. Recombination events were detected between loci (c.−40, c.−37) in the 5′UTR and (c.373+18, c.373+101) and (c.373+101, c.373+241) in intron I. Single-nucleotide polymo…
Specific roles of 5′ RNA secondary structures in stabilizing transcripts in chloroplasts
2005
RNA secondary structures, e.g. stem-loops that are often found at the 5' and 3' ends of mRNAs, are in many cases known to be crucial for transcript stability but their role in prolonging the lifetime of transcripts remains elusive. In this study we show for an essential RNA-stabilizing stem-loop at the 5' end of rbcL gene transcripts in Chlamydomonas that it neither prevents ribonucleases from binding to the RNA nor impedes their movement along the RNA strand. The stem-loop has a formative function in that it mediates folding of a short sequence around its base into a specific RNA conformation, consisting of a helical and single-stranded region, i.e. the real structure required for longevit…
In Silico Analysis of the Novel Variant Q375R in the Phenylalanine Hydroxylase Gene
2019
Background: Phenylketonuria is an inborn metabolic disorder inherited in an autosomal recessive pattern. The detection of pathogenic variations improves the power of at-risk carrier and prenatal detection. We previously found Q375R a novel phenylalanine hydroxylase variation in phenylketonuria patients from the south-west of Iran. Objectives: Here, we aimed to evaluate the rate of the pathogenicity of this novel variant and three other intron variants (IVS9 + 32insA, IVS11 + 163delC, and IVS12 + 30C>T). Methods: The pathogenicity and some structural features of Q375R were analyzed using bioinformatics tools including SIFT, PolyPhen, Mutpred, MutationTaster, nSSNP Analyzer, SNP effect, 3DLig…
Stage, tissue, and cell specific distribution of alternative Ultrabithorax mRNAs and protein isoforms in the Drosophila embryo
1996
The homeotic gene Ultrabithorax encodes a family of six homeoproteins translated from alternatively spliced mRNAs. The structures of these UBX isoforms have been conserved among anciently diverged Drosoph-ila species and functional distinctions between some isoforms have been reported that suggest subtle but important roles in Ubx action. We present a detailed analysis of the expression patterns of Ubx mRNAs and proteins during embryogenesis, using isoform-specific monoclonal antibodies and synthetic oligonucleotide probes. These patterns are remarkably complex, each mRNA and corresponding protein isoform being expressed in a partially overlapping but distinct stage and tissue-specific patt…
The IStron CdISt1 of Clostridium difficile: molecular symbiosis of a group I intron and an insertion element
2003
Abstract The IStron CdISt1 was first discovered as an insertion into the tcdA gene of the clinical isolate C34. It combines structural and functional properties of a group I intron at its 5′-end with those of an insertion element at its 3′-end. Up to date four different types could be found, mainly differing in their IS-element portions. Contrasting classical group I introns, CdISt1 is always integrated in ORFs encoding bacterial protein. In case CdISt1 had only the IS-element function such insertion would inactivate the protein encoded by the host gene. It is only due to the self-splicing activity of the group I intron parts that CdISt1 integration does not abolish protein function. Both e…
Analysis of sequence variations in the LDL receptor gene in Spain: general gene screening or search for specific alterations?
2006
Abstract Background: Familial hypercholesterolemia (FH) is a frequent form of autosomal-dominant hypercholesterolemia that predisposes to premature coronary atherosclerosis. FH is caused by sequence variations in the gene coding for the LDL receptor (LDLR). This gene has a wide spectrum of sequence variations, and genetic diagnosis can be performed by 2 strategies. Methods: Point variations and large rearrangements were screened along all the LDLR gene (promoter, exons, and flanking intron sequences). Results: We screened a sample of 129 FH probands from the Valencian Community, Spain, and identified 54 different LDLR sequence variations. The most frequent (10% of cases) was 111insA, and 60…
A chimeric ribozyme in Clostridium difficile combines features of group I introns and insertion elements
2002
CdlSt1, a DNA insertion of 1975 bp, was identified within tcdA-C34, the enterotoxin gene of the Clostridium difficile isolate C34. Located in the catalytic domain A1-C34, Cd/St1 combines features of two genetic elements. Within the first 434 nt structures characteristic for group I introns were found; encoding the two transposase-like proteins tlpA and tlpB nucleotides 435-1975 represent the remainder of a IS605-like insertion element. We show that the entire CdlSt1 is accurately spliced from tcdA-C34 primary transcripts and that purified TcdA-C34 toxin is of regular size and catalytic activity. A search for CdlSt1-related sequences demonstrates that the element is widespread in toxinogenic…
Polymorphism and chromosomal localization of the porcine signal transducer and activator of transcription 5B gene (STAT5B).
2006
Signal transducers and activators of transcription (STATs) are a family of transcription factors. STAT5A and 5B are two highly related proteins encoded by two distinct genes. Transgenic knockout mice studies have indicated the importance of STAT5 proteins for the regulation of both lactation and growth performance. Moreover, different studies determine the role of STAT5 proteins in the modulation of adipocyte function. In this study, we sequenced one fragment of STAT5B gene from animals of six breeds (Duroc, Iberian, Landrace, Large White, Pie´train and Meishan) to identify genetic variants. A G/A single nucleotide polymorphism in intron 14 creates a polymorphic PstI restriction site and wa…
Structures of two molluscan hemocyanin genes: significance for gene evolution.
2001
We present here the description of genes coding for molluscan hemocyanins. Two distantly related mollusks, Haliotis tuberculata and Octopus dofleini , were studied. The typical architecture of a molluscan hemocyanin subunit, which is a string of seven or eight globular functional units (FUs, designated a to h, about 50 kDa each), is reflected by the gene organization: a series of eight structurally related coding regions in Haliotis , corresponding to FU-a to FU-h, with seven highly variable linker introns of 174 to 3,198 bp length (all in phase 1). In Octopus seven coding regions (FU-a to FU-g) are found, separated by phase 1 introns varying in length from 100 bp to 910 bp. Both genes exh…