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)

Genomic DNA was prepared from four reference strains of Mycobacterium paratuberculosis and 46 isolates of this organism from New Zealand, Australia, Canada, and Norway and also from two mycobactin-dependent "wood pigeon" strains. The DNA was characterized by restriction endonuclease analysis, both with and without DNA hybridization, with a probe specific to a repetitive DNA sequence in M. paratuberculosis. Both techniques differentiated M. paratuberculosis strains into two groups, but DNA hybridization revealed more differences between strains within the larger group. All the strains from cattle and many strains from other animals belonged to this group. The second group of nine strains included the Faroe Islands strain, all New Zealand sheep strains, and one New Zealand goat strain. Primary isolation of strains belonging to this group was difficult to achieve. DNA from acid-fast organisms harvested directly from intestinal tissues of sheep with Johne's disease was shown to have restriction and hybridization patterns identical to those of DNA obtained from M. paratuberculosis isolates cultured from the same tissues. Two Norwegian goat strains and the wood pigeon strains did not hybridize to the M. paratuberculosis probe and had restriction patterns very different from those of other M. paratuberculosis strains. The wood pigeon strains had restriction patterns very similar to those of strains of Mycobacterium avium, indicating that they should be classified as that species. The presence of two distinct groups of M. paratuberculosis strains and their predominant distribution in different host animals may be significant in management of mixed-animal farming operations.
 ...
PMID:Identification of two groups of Mycobacterium paratuberculosis strains by restriction endonuclease analysis and DNA hybridization. 216 89

The number of rRNA genes in Mycobacterium smegmatis was examined by hybridization of BamHI and SalI digests of chromosomal DNA with 3'-end-labeled 5S, 16S, 23S rRNA and tRNA. Each RNA probe gave two hybridization bands. The PstI fragments of 6.6 kilobases were cloned to pBR322. The cloned DNA was characterized by restriction endonuclease mapping, DNA-RNA hybridization, and the R-loop technique.
 ...
PMID:Study on rRNA genes in Mycobacterium smegmatis. 246 81

A genomic library of Mycobacterium tuberculosis strain Aoyama B in Escherichia coli K-12 was constructed by cloning Sau 3A I cleaved M. tuberculosis Aoyama B chromosomal DNA into pUC18, pUC181 or pUC182. Clones reacting with anti-PPDs-rabbit-serum were screened by immunoblotting among 3 x 10(4) clones. Seven clones were selected; designating pAT 01, pAT 101, pAT 102, pAT 103, pAT 104, pAT 105 and pAT 201. On Western blotting, they were shown to produce 15 kD (pAT 01, pAT 101, pAT 105), 18 kD (pAT 103) and 60 kD (pAT 102, pAT 201) peptide antigens. Restriction endonuclease map of each of the above clones was composed, and putative coding frames of anti-PPDs-rabbit-serum reactive peptides were deduced by analysing deletion derivatives. Nucleotide sequence of pAT 01, encoding for 15 kD peptide antigen was analyzed, and a Hinf I-Hinf I fragment in pAT 01 was subcloned into pUC 18 lambda CPL 1 to determine the direction of its reading frame. The origin of promoter that drives cloned mycobacterial genes in E. coli was discussed.
 ...
PMID:[Molecular cloning and expression of Mycobacterium tuberculosis strain Aoyama B peptide antigen genes in Escherichia coli--a gene encoding 15 kD antigen (AT 01)]. 250 18

The inability to cultivate Mycobacterium leprae in vitro has severely hampered comprehensive phenotypic analysis of individual isolates, leaving unanswered the question of the relatedness of these isolates. Since the nucleotide sequence of a bacterial chromosome is its "genetic fingerprint", we have employed the use of restriction fragment length polymorphism (RFLP) analysis of chromosomal DNA of M. leprae isolates to assess the relatedness among these isolates. DNA of M. leprae was harvested from infected armadillo tissue originally inoculated with bacilli from lepromatous lesions of human patients from geographically distinct regions of the world. Restriction endonuclease (EcoRI, PstI, and PvuI) digests of chromosomal DNA were analysed using DNA probes encoding all or part of the 28-kDa, 65-kDa and 70-kDa proteins of M. leprae. Comparison of the resultant autoradiographs showed that the RFLP patterns were all identical indicating that these isolates contained no polymorphism with respect to the restriction endonuclease sites analysed. These results indicated that the M. leprae isolates tested in this study were indistinguishable at the genotypic level, suggesting the possibility of homogeneity among members of the species, M. leprae.
 ...
PMID:A study of the relatedness of Mycobacterium leprae isolates using restriction fragment length polymorphism analysis. 256 1

Mycobacterium paratuberculosis strains, mycobacteria from patients suffering from Crohn's disease, "wood pigeon mycobacteria," and representatives of Mycobacterium avium-Mycobacterium intracellulare were compared by restriction endonuclease DraI digestion and field inversion gel electrophoresis. Characteristic profiles were seen for M. paratuberculosis, including isolates from patients suffering from Crohn's disease, for wood pigeon mycobacteria, and for M. avium-M. intracellulare serotypes 2, 16, 18, and 19. Two M. paratuberculosis strains used for vaccine production (St 18 and 316 F) presented patterns different from those of the other M. paratuberculosis strains. Strains St 18 yielded a pattern identical to that of the M. avium type strain serotype 2, whereas 316 F gave a unique pattern. The method developed in this study represents a useful taxonomic tool for the identification and classification of mycobacteria.
 ...
PMID:DNA polymorphism in Mycobacterium paratuberculosis, "wood pigeon mycobacteria," and related mycobacteria analyzed by field inversion gel electrophoresis. 257 86

The DNA from 31 isolates and a reference strain of Mycobacterium paratuberculosis was digested individually with restriction endonucleases BstE II and Pst I. DNA fragments were separated by gel electrophoresis and analyzed. The isolates were from 23 American states, Argentina and Nova Scotia. Twenty-seven were isolated from cattle, two from goats and two from sheep. With the exception of one isolate from cattle, all had restriction endonuclease fragment patterns identical to the fragment patterns for the reference strain, M. paratuberculosis ATCC 19698T. These results confirm other reports and indicate that organisms identified as typical M. paratuberculosis isolates are genetically very similar. It may be possible to use restriction endonuclease analysis to differentiate isolates of M. paratuberculosis from other slowly growing mycobacteria. The genetic similarity also indicates that it may be possible to develop a diagnostic probe that is specific for M. paratuberculosis.
 ...
PMID:Analysis of restriction endonuclease fragment patterns of DNA from Mycobacterium paratuberculosis. 278 28

Organisms belonging to the Mycobacterium avium-M. intracellulare-M. scrofulaceum (MAIS) serocomplex were subjected to restriction endonuclease analysis (REA) with the enzymes BstEII, PvuII, and BclI. Substantial genetic heterogeneity was observed between members of an authenticated collection of the 31 serotypes. Serotypes 2 and 3 were indistinguishable, however, as were serotypes 5 and 10. No direct correlation could be made between restriction pattern and species identification. REA of serotype 2 and serotype 8 isolates from various geographic locations and animal origins showed that, within limits, the restriction pattern could be used as an index of serotype. Some isolates that were unable to be classified serologically exhibited restriction patterns identical to those of strains that were able to be classified by seroagglutination. The difficulty of interpreting much of the epidemiological data concerning MAIS organisms may be partially explained by the extent of heterogeneity observed by REA. These findings support the contention that the MAIS complex has a substantially greater degree of heterogeneity than has been revealed by traditional methods.
 ...
PMID:Restriction endonuclease analysis of members of the Mycobacterium avium-M. intracellulare-M. scrofulaceum serocomplex. 282 14

DNA preparations from 24 New Zealand isolates, two reference strains of Mycobacterium bovis, and one reference strain each of Mycobacterium microti, Mycobacterium africanum, and Mycobacterium tuberculosis were characterized by restriction endonuclease analysis. Twenty-five restriction enzymes were investigated. The clearest differences in M. bovis patterns were obtained with the enzymes BstEII and BclI. These produced four and five different patterns, respectively, for the 24 local isolates. When the results from both enzymes were considered, seven different combinations were obtained. The patterns produced for the two reference strains of M. bovis could be distinguished from each other and also from the patterns produced for the local isolates. All patterns were reproducible and are now being used for typing M. bovis isolates. With either enzyme, the patterns produced for the M. tuberculosis, M. bovis, and M. africanum strains had many features in common, but all the M. bovis patterns were clearly more similar to each other than to the M. tuberculosis patterns. The patterns produced for the M. microti strain were markedly different from those produced for the other species. Restriction endonuclease analysis is clearly a useful method for inter- and intraspecific classifications of the tuberculosis complex.
 ...
PMID:DNA restriction endonuclease analysis of Mycobacterium bovis and other members of the tuberculosis complex. 298 47

DNA was isolated from Mycobacterium phlei and from M. smegmatis. Each DNA sample was restricted with endonucleases, the fragments were separated by agarose gel electrophoresis and transferred to nitrocellulose film. Fragments of DNA containing rRNA sequences were identified by means of 125I-labelled rRNA of M. phlei or of M. smegmatis. The distributions of restriction endonuclease sites within the rRNA gene(s) and flanking sequences were found to be characteristic for each of the two species. Hybridizations with heterologous probes indicate that although M. phlei rRNA and M. smegmatis rRNA share regions of sequence homology, they are probably not identical in primary structure. The results suggest that the rRNA genes might prove to be useful taxonomic markers for mycobacteria.
 ...
PMID:Evidence for genetic divergence in ribosomal RNA genes in mycobacteria. 300 53

A method for the isolation of DNA from mycobacteria propagated in vitro is described that utilizes organic solvents to extract lipoidal components from the outer membrane, and digestion with a protease (nagarse) and lysozyme to penetrate the cell wall. The mycobacterial cells were lysed by the addition of detergent and the DNA was purified by digestion with pronase, sequential phenol and chloroform extractions, and digestion with RNAase A. The isolated DNA, which was obtained in good yields, was of a relatively high Mr and could be readily digested by restriction endonucleases. By this method, the genomes of Mycobacterium avium, M. intracellulare, M. lepraemurium, 'M. lufu', M. marinum, M. phlei, M. scrofulaceum, M. smegmatis and M. tuberculosis were isolated and the restriction endonuclease digestion patterns analysed. Each species could be distinguished by the digestion patterns, indicating that this approach can be used for identifying mycobacterial species. This approach is also sufficiently sensitive to differentiate strains since we were able to distinguish two independently isolated strains of M. tuberculosis, H37 and H4. In addition, no evidence was obtained for the presence of methylcytosine residues in the sequences 5'.CCGG.3',5'.CCCGGG.3',5'.CC(A/T) GG.3' or for methyladenine at 5'.GATC.3' in the DNA of the nine mycobacterial species examined using pairs of restriction enzymes that recognize and cleave at the same nucleotide sequence but differ in their sensitivity to 5-methylcytosine or 6N-methyladenine.
 ...
PMID:Isolation and restriction endonuclease analysis of mycobacterial DNA. 301 65


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>