Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new enforcement (kyosei-) cloning plasmid vector, designated pKF4, was constructed which confers kanamycin resistance (KmR) and enforces streptomycin sensitivity (SmS). Since it is important to employ restriction endonuclease (ENase) preparations free of exonuclease (Exo) activities for effective use of the kyosei-cloning procedure [Hashimoto-Gotoh et al., Gene 137 (1993) 211-216], ENases such as HpaI and SmaI purchased from four different suppliers were examined for possible contamination by exonucleases using pKF4. The plasmid DNA was digested with either ENase, ligated and transformed into Escherichia coli mutants, rpsL, supE, trpR. With pKF4 intact DNA (approx. 8 ng), 2.3 x 10(5) KmR transformant and four KmRSmR transformant colonies were obtained; the efficiency of transformation plating (ETP) of the intact DNA was approx. 2 x 10(-5). On the other hand, the ETP values were significantly higher by one to three orders of magnitude when cut and re-joined DNAs were used under the same conditions in six out of eight ENase samples examined. The results indicate that even commercially supplied ENases, that should have passed their quality control test, could have been contaminated with Exo sufficient to interfere with effective use of the kyosei-cloning method. Therefore, it is advisable to examine ENase samples for possible contamination with Exo activities, in order to choose the right preparations for this method at the beginning of the experiments.
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PMID:Detection of exonuclease activities in restriction endonuclease preparations using an enforcement plasmid for kanamycin-resistance selection. 759 Mar 18

The distribution of glycoprotein B (gB) among different human herpesvirus 6 (HHV-6) strains was analysed with a panel of three monoclonal antibodies (MAbs) derived from mice immunized with U1102-infected lymphocytes. MAb 2D9 reacted specifically by immunofluorescence and immunoprecipitation with the U1102 and GS isolates, and failed to react with Z29 and the variant B strains Hashimoto and SF. In addition, Z29, Hashimoto and SF gB had a lower M(r) than U1102 and GS gB. MAb 2D9 also failed to react with the exanthem subitum isolate CV, included in this study as an as yet poorly characterized isolate. Consistent with this result, CV failed to react with the variant A-specific MAb to gp82-105 and behaved as a variant B virus even with respect to the diagnostic HindIII endonuclease restriction cleavage site located in a fragment hybridizing to the pZVH14 probe. By contrast with MAb 2D9, MAbs 2B9 and 2D10 reacted with all of the isolates tested, strengthening the argument tha they have common epitopes. Based on the antigenic and M(r) specificities of gB, the HHV-6 isolates tested were arranged into two non-overlapping clusters, which closely parallel the variant A and B strain groups, defined previously by several criteria, including restriction endonuclease polymorphism, antigenic variations, growth in in vitro cultures and sequence analyses.
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PMID:Monoclonal antibodies to glycoprotein B differentiate human herpesvirus 6 into two clusters, variants A and B. 840 48

In order to investigate the association of TCR Cbeta and immunoglobulin (Ig) VH polymorphisms with thyroid autoimmune diseases (TAD), we analyzed restriction-endonuclease-generated polymorphisms using T-cell receptor (TCR) Cbeta and VH gene-family-specific probes. We tested genomic DNAs of patients isolated from a large family affected with Graves' disease and Hashimoto's thyroiditis as well as the genomic DNA of unrelated Tunisian controls. Hybridization of BglII-digested DNA with a TCR Cbeta probe revealed two alleles of 9.2 and 10 kb. These Cbeta polymorphisms have already been found in the Caucasian population. However, there was no abnormal distribution of this polymorphism in patients with TAD, compared to related healthy individuals and to unrelated Tunisian controls. Besides, there was a low VH polymorphism in members of the family affected with TAD. Analysis of the Ig gene families revealed no restriction site polymorphism pattern specific for TAD.
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PMID:Analysis of immunoglobulin VH and TCR cbeta polymorphisms in a large family with thyroid autoimmune disorder. 1057 72

We have investigated the molecular basis of selective and complete C1s deficiency in 2-year-old girl with complex autoimmune diseases including lupus-like syndrome, Hashimoto's thyroiditis, and autoimmune hepatitis. This patient's complement profile was characterized by the absence of CH50 activity, C1 functional activity <10%, and undetectable levels of C1s Ag associated with normal levels of C1r and C1q Ags. Exon-specific amplification of genomic DNA by PCR followed by direct sequence analysis revealed a homozygous nonsense mutation in the C1s gene exon XII at codon 534, caused by a nucleotide substitution from C (CGA for arginine) to T (TGA for stop codon). Both parents were heterozygous for this mutation. We used the new restriction site for endonuclease Fok-1 created by the mutation to detect this mutation in the genomic DNA of seven healthy family members. Four additional heterozygotes for the mutation were identified in two generations. Our data characterize for the first time the genetic defect of a selective and complete C1s deficiency in a Caucasian patient.
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PMID:Molecular basis of a selective C1s deficiency associated with early onset multiple autoimmune diseases. 1139 May 18

2-Deoxyribonolactone (L) and the C4'-oxidized abasic site (C4-AP) are produced by a variety of DNA-damaging agents. If not repaired, these lesions can be mutagenic. Exonuclease III and endonuclease IV are the major enzymes in E. coli responsible for 5'-incision of abasic sites (APs), the first steps in AP repair. Endonuclease III efficiently excises AP lesions via intermediate Schiff-base formation. Incision of L and C4-AP lesions by exonuclease III and endonuclease IV was determined under steady-state conditions using oligonucleotide duplexes containing the lesions at defined sites. An abasic lesion (AP) in an otherwise identical DNA sequence was incised by exonuclease III or endonuclease IV approximately 6-fold more efficiently than either of the oxidized abasic sites (L, C4-AP). Endonuclease IV incision efficiency of 2-deoxyribonolactone or C4-AP was independent of whether the lesion was opposite dA or dG. 2-Deoxyribonolactone is known to cross-link to endonuclease III (Hashimoto, M. (2001) J. Am. Chem. Soc. 123, 3161.). However, the C4-AP lesion is efficiently excised by endonuclease III. Oxidized abasic site repair by endonuclease IV and endonuclease III (C4-AP only) is approximately 100-fold less efficient than repair by exonuclease III. These results suggest that the first step of C4-AP and L oxidized abasic site repair will be the same as that of regular AP lesions in E. coli.
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PMID:Repair of oxidized abasic sites by exonuclease III, endonuclease IV, and endonuclease III. 1520 14

Graves' disease (GD) and Hashimoto's thyroiditis (HT) are both common autoimmune diseases of the thyroid gland (AITD). The IL-4 is involved in both humoral and cellular immunity. The aim of this study was to test whether the IL-4 gene could be used as a genetic marker to predict the development of AITD amongst the Chinese population of Taiwan. For this study, a normal control group of 105 healthy subjects and two experimental groups featuring individuals afflicted with either GD (104 patients) or HT (109 patients) were examined. Polymerase chain reaction (PCR) was used to analyze the variable number of tandem repeats (VNTRs) polymorphism for the IL-4 gene intron 3 and PCR-based restriction analysis using endonuclease BsmFI was undertaken for the same gene at the promoter -590 position. We found no significant difference in the frequencies of presence of genotype and allelic variants for the IL-4 gene at both the intron 3 and the promoter regions between the normal control group and each of the two patient groups. These findings suggest that the IL-4 gene polymorphisms that arise at either intron 3 or promoter -590 positions are not suitable genetic markers for AITD among Taiwanese Chinese.
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PMID:Lack of association between interleukin-4 gene polymorphisms and autoimmune thyroid diseases amongst Taiwanese Chinese. 1805 60