Search results for "Sequence analysi"
showing 10 items of 1351 documents
Improved acid tolerance of a recombinant strain of Escherichia coli expressing genes from the acidophilic bacterium Oenococcus oeni.
2001
Aims:Oenococcus oeni is a lactic acid bacterium used in wine fermentation. Two open reading frames (orfB and orfC) were identified in the upstream region of the hsp18 gene, encoding the small heat-shock protein Lo18. Expression of these genes in conditions of acid stress was studied in Escherichia coli. Methods and Results: Sequence analysis showed that orfB encodes a putative transcriptional regulator of the LysR family. The protein encoded by orfC shares homologies with multi-drug resistance systems. Heterologous expression of orfB, orfC and hsp18 genes in Escherichia coli significantly enhanced the viability of the host strain under acidic conditions. Conclusions: It was demonstrated tha…
Sequence analysis of the rDNA spacer of Paracentrotus lividus and observations about pre-rRNA processing. NTS sequence of Paracentrotus lividus rDNA.
1993
We have isolated and sequenced one intergenic region and a small part of the flanking regions (18S and 26S rRNA coding regions) of the rRNA-encoding genes (rDNA) from the sea urchin Paracentrotus lividus. This region is about 3.8 Kb long. Northern blot hybridizations and S1 mapping experiments demonstrated the presence of a partially processed 21S rRNA precursor while has the same 5' terminus as the 32S primary precursor, also in developmental stages characterized by a low rate of rRNA synthesis.
Phylogenetic relationship of ubiquitin repeats in the polyubiquitin gene from the marine sponge Geodia cydonium
1994
Ubiquitin is a 76-residue protein which is highly conserved among eukaryotes. Sponge (Porifera) ubiquitin, isolated from Geodia cydonium, is encoded by a gene (termed GCUBI) with six repeats, GCUBI-1 to GCUBI-6. All repeat units encode the same protein (with one exception: GCUBI-4 encodes ubiquitin with a change of Leu to Val at position 71). On the nt level the sequences of the six repeats differ considerably. All changes (except in GCUBI-4) are silent substitutions, which do not affect the protein structure. However, there is one major difference between the repeats: Codons from both codon families (TCN and AGPy) are simultaneously used for the serine at position 65. Using this characteri…
Genetic organization of the mle locus and identification of a mleR-like gene from Leuconostoc oenos
1996
Characterization of the mle locus harboring the malolactic enzyme gene mleA and malate permease gene mleP from Leuconostoc oenos was completed in this study by mRNA analysis. Northern (RNA) blot experiments revealed a 2.6-kb transcript, suggesting an operon structure harboring mleA and mleP genes. Primer extension analysis showed that the mle operon has a single transcription start site located 17 nucleotides upstream of the ATG translation start site for the mleA gene. We found sequences, TTGACT and TATGAT (which are separated by 18 bp), that are closely related to the gram-positive and Escherichia coli consensus promoter sequences. Upstream of the mleA gene, an 894-bp open reading frame t…
The Histidinol Phosphate Phosphatase Involved in Histidine Biosynthetic Pathway Is Encoded by SCO5208 (hisN) in Streptomyces coelicolor A3(2)
2008
Through the screening of a Streptomyces coelicolor genomic library, carried out in a histidinol phosphate phosphatase (HolPase) deficient strain, SCO5208 was identified as the last unknown gene involved in histidine biosynthesis. SCO5208 is a phosphatase, and it can restore the growth in minimal medium in this HolPase deficient strain when cloned in a high or low copy number vector. Moreover, it shares sequence homology with other HolPases recently identified in Actinobacteria. During this work a second phosphatase, SCO2771, sharing no homologies with SCO5208 and all so far described phosphatases was identified. It can complement HolPase activity mutation only at high copy number. Sequence …
Two changes of the same nucleotide confer resistance to diuron and antimycin in the mitochondrial cytochrome b gene of Schizosaccharomyces pombe
1988
AbstractDiuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and antimycin, both inhibitors of mitochondrial respiration, block electron flow between cytochromes b and c1. Mutants resistant to either drug have been selected using Schizosaccharomyces pombe strains with an extrachromosomally inherited mutator. In analogy to Saccharomyces cerevisiae these mutational sites were assumed to map in the cytochrome b gene. DNA sequence analysis showed that two changes in the same nucleotide are responsible for resistance to antimycin and diuron. Analysis of resistant and sensitive progeny of crosses between the mutants and the wild type confirmed the correlation between mutational alteration and resista…
Whole-Genome Sequence of Stenotrophomonas maltophilia D457, a Clinical Isolate and a Model Strain
2012
ABSTRACT Stenotrophomonas maltophilia is an opportunistic pathogen with an environmental origin, and it is an increasingly relevant cause of nosocomial infections. Here we present the whole-genome sequence of S. maltophilia strain D457, a clinical isolate that is being used as a model for studying antibiotic resistance in this bacterial species.
Purification and partial amino acid sequences of the enzyme vinorine synthase involved in a crucial step of ajmaline biosynthesis.
2004
The acetyl-CoA-dependent enzyme vinorine synthase was isolated from hybrid cell suspension cultures of Rauvolfia serpentina and Rhazya stricta. The sarpagan-type alkaloid gardneral was used as a substrate of the enzyme leading to the ajmalan-type 10-methoxyvinorine. An HPLC-based assay was developed to monitor vinorine synthase activity, which allowed establishing a five step purification procedure combining anion exchange, hydrophobic interaction, hydroxyapatite and gel filtration. Purification resulted in a yield of 0.2% and an approximately 991-fold enrichment of the acetyltransfer activity. SDS-PAGE analysis showed a Mr for the enzyme of approximately 50 kDa. The four peptide fragments …
Analysis of the Overdispersed Clock in the Short-Term Evolution of Hepatitis C Virus: Using the E1/E2 Gene Sequences to Infer Infection Dates in a Si…
2006
Abstract The assumption of a molecular clock for dating events from sequence information is often frustrated by the presence of heterogeneity among evolutionary rates due, among other factors, to positively selected sites. In this work, our goal is to explore methods to estimate infection dates from sequence analysis. One such method, based on site stripping for clock detection, was proposed to unravel the clocklike molecular evolution in sequences showing high variability of evolutionary rates and in the presence of positive selection. Other alternatives imply accommodating heterogeneity in evolutionary rates at various levels, without eliminating any information from the data. Here we pre…
A Bacillus thuringiensis strain producing epizootics on Plodia interpunctella: A case study
2012
Abstract After several disease outbreaks in laboratory cultures of pyralid moths in Tabriz University, Iran, during 2004 and 2005, a new Bacillus thuringiensis aizawai strain EF495116 (BTA) was isolated from a dead Plodia interpunctella larva. A complete characterization of the strain was performed, including serological identification, protein and plasmid pattern determination, a PCR-based identification of virulence-related genes, nucleotide sequence analysis of the 16S rDNA and gyrB genes (in order to find out relationships between the species with other virulent Bacillus pathogens), and biological activity assays. These studies revealed that BTA produced a major parasporal protein band …