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

Three novel restriction fragment length polymorphisms (RFLPs) have been identified using a pan-HLA class I probe and the endonuclease SstI. This study, in conjunction with previously reported SstI RFLPs, now allows the identification of the HLA-crossreacting antigens Aw19 (A29/30/31/32/w33), A23/24 and A3/11 by specific hybridization patterns with a single enzyme/probe combination. Three of the corresponding polymorphic SstI restriction sites map within the HLA-A gene and generate two allelic RFLPs (5.06, 5.92 kb) and one single RFLP (5.92 kb) that show an absolute correlation with HLA-A23/24 and A29/32 crossreacting antigens, respectively. However, other SstI RFLPs (7.97, 9.4, 9.6, 9.8 and 13.34 kb), also linked to HLA-A crossreacting antigens, map outside the HLA-A gene and probably correspond to non-HLA-A,B,C class I genes in strong linkage disequilibrium with the HLA-A gene. These data show that HLA-A crossreacting antigens share more SstI RFLPs than neighboring non-HLA-A,B,C class I genes or pseudogenes; also, this has raised the possibility that some crossreacting HLA-A alloantisera might additionally recognize shared antigenic determinants in non-HLA-A,B,C proteins since the HLA-Aw19 crossreactivity cannot be fully explained by analyzing the HLA-A amino acid sequence.
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PMID:Shared SstI RFLPs by HLA-Aw19, A23/24 and A3/11 crossreacting groups. 197 78

In the past few years it has been possible by combining enzymatic cleavage of genomic DNA and the Southern blot hybridization technique to explore the endonuclease recognition site polymorphism of the MHC. HLA class I and DR and DQ alpha and beta class II specific probes as well as human C4 and Bf class III probes were used. All these probes were shown to cross-hybridize with DNA from pigs, cattle, sheep and horses. Hybridization of human genomic DNA with a class I probe showed 15-25 bands per genome depending on the enzyme used. Distinct endonucleases generated clusters of restriction fragments (RF) in HLA-informative families which correlated with HLA specificities. While numerous clusters were found associated with HLA-A alleles almost no cluster was related to HLA B or C specificities. Similarly, class II probes provided a large number of clusters. The existence of these clusters suggested that some polymorphic restriction sites are found in strong linkage disequilibrium and that the underlying mechanism might be gene conversion with heteroduplex correction. Since the degree of polymorphism detected by RF appears to be greater than the polymorphism defined by more traditional methods stronger associations between RF and pathological conditions are to be expected. Southern blot analysis was applied to unrelated pigs and sheep, as well as to families. Preliminary studies have also been performed on a few unrelated cattle and horses. Depending on the endonuclease used the HLA class I probe hybridized with around 15 bands in MHC heterozygous pigs and ruminants while up to 20 bands were found in horses. Therefore, a several-fold greater number of potential class I genes exist compared to those actually expressed. With the class II beta probe, cattle and sheep showed around 10 bands whereas 15 were observed in pigs and around 20 in horses. Based on limited results obtained with DQ alpha and beta probes and with the DR alpha probe there appeared to be fewer of these respective genes. Only one C4 gene has been detected in pig and this gene maps within the SLA region. Hybridization with the human C4 probe in cattle, sheep and horses revealed two to four bands which could possibly account for two C4 genes. To date their linkage to the MHC has not been established. The Southern blot hybridization technique represents a powerful tool for future immunogenetic studies.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:DNA polymorphism in the major histocompatibility complex of man and various farm animals. 242 96

Analysis of polymorphic DNA endonuclease restriction fragments by Southern blotting indicates that the genetic complexity of the HLA class I gene family is larger than the complexity indicated by serologically defined HLA-A, -B and -C gene products (Orr et al., 1982). There are correlations between polymorphic restriction endonuclease fragments in a limited number of HLA class I alleles; in fact, a few alleles in the population have been correlated with the presence of polymorphic DNA fragments (Cann et al., 1983; Cohen et al., 1983; Orr & De Mars, 1983; Lucotte, Coulondre & Salmon, 1985; Driesel et al., 1985). Recently, probes shown to be specific for HLA-A and HLA-B genes (Grumet et al., 1983; Koller et al., 1985) were constructed from the 3'-untranslated region of these genes.
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PMID:DNA polymorphisms associated with HLA-B-like genes and evidence for a duplication of B40 genes detected with an HLA-B-specific DNA probe. 288 13

Restriction enzyme site polymorphisms for Pvu II endonuclease are examined in a panel of DNAs isolated from peripheral blood lymphocytes of HLA-typed individuals. 21 polymorphic bands are detected from a total of 39 restriction fragments analyzed, only 9 of them corresponding to common variable morphs. Three polymorph fragments only correlate with known HLA-A and -B serologic alleles.
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PMID:Correlation of class I DNA Pvu II restriction HLA gene fragments with serologic alleles. 290 2

Cellular DNA from HLA-typed individuals was digested with the restriction endonucleases HindIII, EcoRV, and EcoRI. The separated restriction endonuclease fragments were hybridized with a HLA class I cDNA probe by using the Southern transfer technique. Digestion of cellular DNA with HindIII generated 22 restriction endonuclease fragments, 11 of which showed polymorphism for presence or absence in a population sample. With EcoRV, 13 fragments were identified; 6 showed polymorphism. EcoRI generated 11 fragments, of which 1 was polymorphic. Of these 18 polymorphic fragments generated by the three restriction endonucleases, each of 5 was found to be positively associated with one allele of the HLA-A or -B allelic series (HLA-Aw24, -B8, -B15, -Bw35, and -B40). One fragment was positively associated with two HLA-A series alleles (HLA-A1 and -A11). Another fragment was positively associated with five HLA-B series alleles (HLA-B5, -B7, -B14, -Bw16, and -Bw35) and one fragment was positively associated with alleles at two loci (HLA-B14 and -Cw5). The serologically defined allele HLA-Aw24 was associated with two polymorphic fragments, one association showing a positive correlation and the other a negative correlation. Each informative family studied thus far has shown segregation of the restriction fragment with the associated serologically defined allele. The fragments associated with serologically defined alleles occurred in the population sample studied at low or moderate frequencies. The remaining polymorphic fragments occur at high frequency, suggesting that class I genes not serologically detected show less polymorphism than serologically defined class I genes.
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PMID:Analysis of HLA class I genes with restriction endonuclease fragments: implications for polymorphism of the human major histocompatibility complex. 631 51

Three new allelic forms of the HLA-G DNA sequence (HLA-G*II, HLA-G*III, and HLA-G*IV) have been identified. With the HLA-G*I sequence (previously designated HLA 6.0) as a reference, HLA-G*II shows a silent (G-->A) mutation at the third base of codon 57, HLA-G*III bears a non-synonymous (A-->T), but conservative, (Thr-->Ser) substitution at the first base of codon 31, and HLA-G*IV shows two silent substitutions: (A-->T) at the third base of codon 107 and (G-->A) at the third base of codon 57. A rapid method of singling out each allele on genomic DNA has been developed by using polymerase chain reaction amplification followed by restriction endonuclease treatment. Also, more or less strong linkage disequilibria has been found between most HLA-A alleles and either HLA-G*I or *II, both being the most prevalent alleles in the population, with a genotypic frequency of 0.55 and 0.38, respectively; HLA-G*III is very rare and HLA-G*IV has a genotypic frequency of 0.07. An evolutive classification of HLA-A alleles results according to their association with either HLA-G*I or HLA-G*II, which does not correlate with the classical serological cross-reacting groups classification. The finding of a strong and selective A/G linkage disequilibria with most HLA-A alleles, together with the existence of less frequent random A/G associations, may suggest that there exist in different haplotypes true and varied A/G genetic distances (and not a recombinational hotspot). It may be inferred from preliminary data that in primates HLA-A/G haplotypes bearing G*II may have appeared later than those bearing G*I.
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PMID:Three new HLA-G alleles and their linkage disequilibria with HLA-A. 810 25