Search

Start Over Subject DNA sequencing

1. Genetic and functional characterisation of Rhodobacter Capsulatus reaction centres carrying triple mutations near to or far from quinone sites

Creator:
Ozkan, S.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
DNA sequencing, L and M subunits, spontaneous mutants, and sub-cloning
Language:
Multiple languages
Description:
In Rhodobacter capsulatus, two triple mutants were constructed. In these non-photosynthetic mutants, two amino acids near the quinone QB have been mutated to two alanines: in the QA site have been mutated to alanine-aspartic acid and glutamic acid-alanine. Several spontaneous mutants derived from original constructs were selected. DNA sequencing experiments on originally designed mutant strains and their spontaneous mutants were performed to identify possible genetic reversions at quinone site-specific locations. Constructed mutants carry double alanines in the QB site and single alanine in the QA site. Spontaneous mutants carry additional compensating mutations, aspartic acid (L225), cysteine (M231), and serine (M231) far from QA and QB sites, which may be involved in quinone binding by the photosynthetic reaction centres.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Genetic diversity and effect of natural selection at apical membrane antigen-1 (AMA-1) among Iranian Plasmodium vivax isolates

Creator:
Rastaghi, Ahmad Reza Esmaeili, Nedaei, Fatemeh, Nahrevanian, Hossein, and Hoseinkhan, Nazanin
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
malaria parasite, vaccine candidate, diversifying selection, Nested-PCR, and DNA sequencing
Language:
English
Description:
Apical membrane antigen-1 (AMA-1) of Plasmodium vivax Grassi et Feletti, 1890 is a promising malaria vaccine candidate. However, antigenic variation is a major problem to design a universal malaria vaccine. Hence, detailed understanding of the pvama-1 gene polymorphism can provide conductive information on this potential vaccine component. Therefore, this study investigated the extent of genetic polymorphisms at domain I (DI), DII and partial DIII of AMA-1 among Iranian P. vivax isolates. Out of 107 blood samples, 92 were analysed based on the quality of the sequencing data. The sequences were classified into 53 haplotypes. Amino acid changes were observed at 31 positions that 17 were located at DI, 11 were at DII and the rest of them (3 positions) were at DIII. Thus, codon polymorphisms at DI were found to be higher than DII. Also, five of these polymorphic codons (D242E, T374P, S389R, Y391F, I395F) were novel and have not been reported yet. Neutrality analysis by using the dN-dS difference (the difference between the rate of non-synonymous and synonymous mutations) showed a negative diversifying selection at DI, DII and across the length of both domains. The potential B-cell epitopes were found in 5 regions of the PvAMA-1 with 10 mutation sites (E145A, K188N, E189N/K/D, K190Q/E, P210S, E227V, D242E, R249H, G253E, K352E), whereas only one mutation (G288E) has been detected in intrinsically unstructured/disordered regions. Fixation index (Fst) estimation between Iranian and Indian isolates (0.0131) indicated a significant low genetic differentiation. Distribution of the polymorphic sites and IURs mapped on a three dimensional structure of PvAMA-1 showed that these regions were located at two opposite faces of the molecule. In conclusion, the results have significant value in the design and development of a malaria vaccine based on this antigen.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Variable expression of hypercholesterolemia in apolipoprotein E2* (Arg136 - Cys) Heterozygotes

Creator:
Jaroslav Hubáček, Jan Piťha, Petr Stávek, Schmitz, G., and Rudolf Poledne
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, sekvenování DNA, metabolismus lipidů, DNA sequencing, lipid metabolism, apolipoprotein E, rare mutation, PCR, 14, and 612
Language:
English
Description:
In the process of population screening for apo E gene polymorphism with the PCR and subsequent restriction analysis, we identified a female who demonstrated heterozygosity for an unusual restriction fragment caused by the loss of a CfoI restriction site. Sequence analysis of the apo E gene was performed and a carrier of the mutant allele with C - T substitution at cDNA position 3817 was identified, which caused an Arg136 - Cys change. The first-line relatives have been screened for this rare mutation with PCR and restriction analysis of PCR products. The complete lipoprotein parameters have been determined in the probands family. In the family, only one child had the same mutant allele as his mother had. The proband (7.49 mmol/l) with her siblings had hypercholesterolemia and a high body mass index (BMI 31.6 kg/m2). By contrast, her son had a normal lipid spectrum with normal BMI. We described the mutation apo E2* (Arg136 - Cys) in a family with elevated lipid levels, but there was no confirmation of the connection between this mutation and type III hyperlipoproteinemia or hyperlipoproteinemia at all. In the case of this mutation, other factors (mainly genetic) are important for the development of lipid metabolism disorders., J. A. Hubáček, J. Piťha, P. Stávek, G. Schmitz, R. Poledne., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public