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)

An endonuclease, present in the microplasmodia of Physarum polycephalum, has been partially purified from isolated nuclei by DEAE-cellulose and Sephadex G-75 chromatography. 1. The endonuclease produced single-strand scissions in double-stranded DNA which resulted in the generation of 5'-phosphoryl and 3'-hydroxyl termini. No activity was observed with single-stranded DNA as substrate. 2. The pH optimum was approximately 8.5. 3. Divalent cations were essential for enzyme activity. MnCl2 and MgCl2 gave maximal activity. CaCl2, ZnCl2 or CoCl2 did not activate the enzyme. 4. The endonuclease activity was highly sensitive to monovalent cations. 5. Endonuclease activity was found in two forms after gel filtration: an activity in a homogeneous peak with a molecular weight of approx. 20 000, and an activity that had a heterogeneous molecular weight and which was isolated in a complex with DNA. A possible function of the endonuclease in DNA replication is discussed.
Biochim Biophys Acta 1977 Sep 20
PMID:Endonuclease activity in nuclei of Physarum polycephalum. Partial purification and characterization. 2 Jan 46

Bacillus subtilis Marburg TI (thy,trpC2) has at least four endonuclease activities as assayed by measuring the conversion of single-stranded circular f1 DNA to the linear form by agarose gel electrophoresis. One of them, which is specific for single-stranded DNA (named endonuclease MII), was purified about 320 times by two chromatographic steps and gel filtration, thereby eliminating exonuclease and phosphomonoesterase activities. This activity requires divalent cations but does not require ATP. The molecular weight estimated by gel filtration was about 57,000 daltons. The cleavage products have 5'-phosphoryl termini. At low concentrations, double-stranded DNA is not split to any detectable extent. At high concentrations, however, double-stranded superhelical DNA is attacked to yield open-circular and linear DNA's. The activity of the enzyme towards single-stranded circular DNA relative to that towards double-stranded linear DNA was calculated to be approximately 5,000:1 by comparing the initial rates of introducing single-strand breaks into the DNA's.
J Biochem 1979 Sep
PMID:Purification and characterization of an endonuclease specific for single-stranded DNA from Bacillus subtilis Marburg. 4 35

Complementary DNA, transcribed in vitro from purified rabbit globin messenger RNA and made double-stranded, has been inserted into Escherichia coli plasmids pSC101 and pMB9 by the poly(dT)/poly(dA) "tailing" and annealing technique. E. coli transformants given by this DNA preparation have been shown to contain globin sequences by the hybridization of globin RNA to DNA from clones grown and lysed in situ on nitrocellulose filters. An estimate of the amount of inserted globin sequences has been provided by fingerprint analysis of globin mRNA sequences hybridized to the purified plasmid chimeras. Inserted sequences so far subjected to detailed analysis have been ascribed to the rabbit beta globin chain. The susceptibility of inserted beta globin, sequences to the restriction endonuclease EcoRI confirms the existence of a site already found through previous nucleotide sequence analysis.
Proc Natl Acad Sci U S A 1976 Sep
PMID:A general method for cloning eukaryotic structural gene sequences. 6 88

A discrete, 600-nucleotide-long plus-strand DNA has been identified among the products of reverse transcription by virions of Moloney murine leukemia virus. Its polarity was shown by hybridization to minus-strand DNA. It appears to be copied from the right end of minus-strand DNA because (i) its restriction endonuclease cleavage pattern corresponds to the redundant 600-base segment found at either end of the ultimate double-stranded reverse transcription products, (ii) its synthesis is actinomycin D sensitive, and (iii) its synthesis begins during the first hour of a reverse transcription reaction when only the right-hand end of minus-strand DNA is available as template. We therefore call this DNA plus-strong-stop DNA by analogy with the minus-strong-stop DNA copied from the left end of the viral RNA. Both strong-stop DNAs are made early during in vitro reactions and decline in concentration later, consistent with postulated roles as initiators of long minus- and plus-strand DNA. Unlike minus-strong-stop DNA, plus-strong-stop DNA remains as a double-stranded nucleic acid after its synthesis, as shown by S1 nuclease resistance. A primer to initiate plus-strong-stop DNA synthesis has not been identified; the product found thus far has no detectable RNA attached to it.
Proc Natl Acad Sci U S A 1979 Sep
PMID:Synthesis of a 600-nucleotide-long plus-strand DNA by virions of Moloney murine leukemia virus. 9 28

The yeast Kluyveromyces lactis synthesizes a beta-galactosidase (EC 3.2.1.32) which is inducible by lactose. We have isolated the gene that codes for this enzyme using recombinant DNA techniques. K. lactis DNA was partially digested with the restriction endonuclease Eco R1 and joined to Eco R1-digested pBR322 plasmid DNA using DNA ligase. ligase. A lac-mutant of Escherichia coli lacking the structural gene for beta-galactosidase was transformed with ligated DNA. Three lac+ transformants containing recombinant plasmids were selected. Two of the plasmids (pK15 and pK17) contain four Eco R1-K. lactis DNA fragments having molecular weights of 2.2, 1.4, 0.55 and 0.5 x 10(6) daltons. The other plasmid (pK16) lacks the smallest fragment. E. coli carrying any of these plasmids produce beta-galactosidase activity that has a sedimentation coefficient and immunological determinants that are nearly identical to K. lactis beta-galactosidase and distinctly different from E. coli beta-galactosidase. DNA-DNA hybridization studies show that the four Eco R1 fragments in pK15 hybridize to K. lactis but not to E. coli DNA.
Cell 1978 Sep
PMID:Molecular cloning and expression in E. coli of a yeast gene coding for beta-galactosidase. 10 Feb 26

Nucleotide sequence analysis and restriction endonuclease mapping have been used to characterize a cDNA copy of immunoglobulin MOPC 21 Kappa mRNA clones in the bacterial plasmid pMB9. Three regions of the inserted cDNA of plasmid pL21-1 have been sequenced and match the known protein sequence at amino acid residues 1-24, 128-138 and 171-179. With these sequences to provide absolute correlations between the restriction map and the structural gene sequence it has been possible to exactly deduce the positions of all 11 of the insert restriction sites mapped within the structural gene. The pL21-1 insert contains the complete variable and constant regions as well as parts of the 3' untranslated and polypeptide leader coding sequences.
Nucleic Acids Res 1978 Sep
PMID:Characterization of an immunoglobin cDNA clone containing the variable and constant regions for the MOPC 21 kappa light chain. 10 Jul 66

Plasmid pUB110 was previously used as a vector to clone fragments of deoxyribonucleic acid that complement the trpC2 mutation in Bacillus subtilis from endonuclease EcoRI digested B. licheniformis, B. pumilus, and B. subtilis cellular deoxyribonucleic acid. Each of several such trp plasmids was subsequently shown to contain a segment of the trp gene cluster on the basis of genetic complementing activity. In the present study, analysis of the Trp enzyme levels in B. subtilis harboring the constructed trp plasmids confirms the genetic constitution of the plasmids. Thus, plasmids that complement mutations in specific trp genes specify the corresponding enzyme activities. The levels of the plasmid-specified Trp enzymes in B. subtilis were generally above the repressed level of the chromosomally specified Trp enzymes and equal to or below the derepressed levels of the chromosomally specified Trp enzymes. Certain cloned trp segments contain a single HindIII-sensitive site. Insertion of HindIII-generated deoxyribonucleic acid fragments into these trp plasmids resulted in inactivation of trpC complementing activity, loss of the trpC-specified enzyme activity, and a 10-fold reduction in the specific activity of the plasmid-specified trpF product. The HindIII insertions had no detectable effect on the level of the trpD product, nor did the insertions detectably alter plasmid-specified complementing activity other than to abolish trpC complementation. Removal of the HindIII insertions was accompanied by recovery of trpC complementing activity and restoration of the trpC-and trpF-determined enzymes to the levels specified by the parent plasmids.
J Bacteriol 1979 Sep
PMID:Insertional inactivation of trpC in cloned Bacillus trp segments: evidence for a polar effect on trpF. 11 80

The endonucleases BglI, BglII, EcoRI, SalI, SmaI, and XbaI were used to fragment the phage SPO2 DNA. Electrophoretic analysis using ethidiumbromide agarose gels showed the phage to have nine BglI sites, one BglII site, four EcoRI sites, one SalI site, one SmaI site, and six XbaI sites. Using partial digestions, multiple endonuclease digestion, and autoradiography the fragments were sized and ordered into a circular map of 23 Md. Such an analysis locates the endonuclease sites, indicates which endonucleases are potentially useful in cloning with SPO2, and allows insertions and/or deletions in the SPO2 DNA to be characterized.
Gene 1979 Sep
PMID:Restriction-fragment map of the temperate Bacillus subtilis bacteriophage SPO2. 11 52

Spontaneous deletion mutants of the bacteriophage SPO2, which are viable and retain their temperate character, were isolated using a heat-EDTA enrichment step. They were identified by endonuclease digestion and agarose-gel electrophoresis of phage DNA. Two of the nine mutants were characterized in detail. Both mutants have a 2.3 Md deletion removing the single BglII site and two of the XbaI fragments. The deletion extends 1.0 Md to one side of the former BglII site and 1.3 Md on the other side. This region of the SPO2 genome is non-essential for either lysogeny or viable phage production and thus is a suitable region for the insertion of exogenous DNA fragments.
Gene 1979 Sep
PMID:Isolation and characterization of viable deletion mutants of Bacillus subtilis bacteriophage SPO2. 11 53

DNA from newborn mice was digested with restriction endonuclease EcoRI, and a 6.6-kilobase fragment encoding immunoglobulin gamma 2b chain mRNA derived from MPC 11 myeloma was enriched about 100-fold by RPC-5 column chromatography and agarose gell electrophoresis. The 6.6-kilobase fragment was cloned with lambda gt WES.lambda B as EK2 vector. The cloned phage (lambda WES.IgH22) contained the constant region gene of the gamma 2b chain but not the variable region gene of MPC 11 mRNA. The constant region genes of the other gamma chains (i.e., gamma 1, gamma 2a, and gamma 3) were not present in lambda gt WES.IgH22 DNA. R-loop mapping indicates that the gamma 2b chain structural gene is divided into two parts (330 +/- 60 SD base pairs and 930 +/- 110 SD base pairs) by an intervening sequence (360 +/- 100 SD base pairs). The nucleotide sequence around the junction of the hinge region and CH2 domain was determined and shown to match the amino acid sequence of the initial part of the CH2 domain of the gamma 2b chain. The base sequence upstream from the junction, however, is unrelated to the amino acid sequence of the CH1 domain and the hinge region of all the gamma chains whose sequences have been determined. These results indicate that the gamma 2b chain gene is interrupted at the junction of the hinge region and CH2 domain by an intervening sequence. The existence of two more intervening sequences, one between the CH1 domain and the hinge region and the other between the CH2 and CH3 domains, is discussed.
Proc Natl Acad Sci U S A 1979 Sep
PMID:Cloning immunoglobulin gamma 2b chain gene of mouse: characterization and partial sequence determination. 11 31


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