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Single Base Substitution (single + base_substitution)
Selected AbstractsPossible involvement in oncogenesis of a single base mutation in an internal ribosome entry site of Epstein,Barr nuclear antigen 1 mRNAJOURNAL OF MEDICAL VIROLOGY, Issue 4 2004Rika Endo Abstract It has been reported recently that the U leader exon located within the 5, untranslated region of Epstein,Barr nuclear antigen 1 (EBNA1) gene contains an internal ribosome entry site (IRES) element. Sequence analysis of the U leader exon was undertaken in samples from 19 patients with infectious mononucleosis and 19 patients with lethal lymphoproliferative diseases and in 15 spontaneously established lymphoblastoid cell lines. The sequence was conserved except for a single base substitution (T-C) at position 67,585. Although the mutation was detected in only one case of infectious mononucleosis, it was found in more than half of the lethal lymphoproliferative diseases and all lymphoblastoid cell lines. The results suggest that a mutation in the IRES element affects EBNA1 gene expression at the translational level and provides Epstein,Barr virus (EBV)-infected cells with a growth advantage, leading to immortalization of cells in vitro and to the development of lethal lymphoproliferative diseases in vivo. J. Med. Virol. 72:630,634, 2004. © 2004 Wiley-Liss, Inc. [source] A new mutation in the linker 12 domain of keratin 5 in a Chinese family with Weber,Cockayne epidermolysis bullosa simplexCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 5 2004J.-G. Li Summary A previously undescribed missense mutation was detected in the L12 domain of keratin 5 (K5) in a Chinese family with Weber,Cockayne epidermolysis bullosa simplex. Direct sequencing of the PCR products identified a single base substitution (983A,G) that changes the aspartic acid residue at codon 328 to glycine in all affected family members, while no mutation was observed either in the healthy individual or 50 unrelated control samples. Asp328 of K5 is remarkably conserved among all type II keratins. D328G is the fourth mutation found to affect this residue in K5-related epidermolysis bullosa simplex, indicating the importance of Asp328 for K5 structure and the dramatic effect that fine changes can have on keratin intermediate filament integrity. [source] Comparative analysis of denaturing gradient gel electrophoresis and temporal temperature gradient gel electrophoresis in separating Escherichia coli uidA amplicons differing in single base substitutionsLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2000A.H. Farnleitner A set of Escherichia coli freshwater isolates was chosen to compare the effectiveness of denaturing gradient gel electrophoresis (DGGE) vs temporal temperature gradient gel electrophoresis (TTGE) for separating homologous amplicons from the respective uidA region differing in one to seven single base substitutions. Both methods revealed congruent results but DGGE showed a five to eight times higher spatial separation of the uidA amplicons as compared with TTGE, although the experiments were performed at comparable denaturing gradients. In contrast to TTGE, DGGE displayed clear and focused bands. The results strongly indicated a significantly higher discrimination efficiency of the spatial chemical denaturing gradient as compared with the temporal temperature denaturing gradient for separating the uidA amplicons. Denaturing gradient gel electrophoresis proved to be highly efficient in the differentiation of E. coli uidA sequence types. [source] | ||||||||||