Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Over 60 producing strains of restriction endonucleases type II have been found among 500 different strains, mostly Enterobacteriaceae. The strain Citrobacter freundii 4111 produces restriction endonuclease CfrBI, a new isoschisomer of StyI. The genes of the restriction-modification system CfrBI were located on the multicopy plasmid pZE8 containing the Co1E1-type replicon and cloned to E. coli K802. The deletion variant of 3.2-kb pZE8 which contains intact restriction-modification and a DNA fragment responsible for autonomous plasmid replication was selected among the recombinant plasmids. The strain with higher R. CfrBI production (at least 10,000,000 U/g cells, which is 500-fold higher than the wild strain) was constructed.
Mol Gen Mikrobiol Virusol
PMID:[Plasmid localization and cloning of restriction modification genes from Citrobacter freundii 4111 strain]. 133 50

The restriction-modification system, named RMMunI, has been purified and characterised from Friend murine erythroleukemia cells. The site-specific endonuclease recognizes and cleaves the 5'C1AATTG nucleotide sequence. RMunI is an isoschizomer of RMfeI from Mycoplasma fermentans. Site-specific methylase modifies the second adenine residue in the same sequence (5'Cam6ATTG). It was established that the discovered enzymatic system is from mycoplasma which contaminates cell lines. Mycoplasma's DNA hybridizes with species-specific DNA probed for Mycoplasma fermentans and Mycoplasma arginini. The possible role of mycoplasmic restriction-modification enzymes in the process of acquired immune deficiency syndrome are discussed.
Mol Biol (Mosk)
PMID:[Mycoplasma restriction-modification system MunI and its possible role in pathogenesis processes]. 140 10

The PvuII endonuclease (PvuIIR) is a restriction enzyme from a type II restriction-modification system of Proteus vulgaris coded on plasmid pPvu1. The protein recognizes the DNA sequence 5' CAG'CTG 3' and shows no sequence homology to other restriction enzymes. This makes PvuIIR an interesting subject for structural determination. A purification procedure was developed that yields milligram quantities of the PvuIIR from plasmids expressed in the Escherichia coli strain HB101. The protein was crystallized using ammonium sulphate as precipitant. The crystals are orthorhombic, space group P2(1)2(1)2 with cell dimensions: a = 84.2 A, b = 106.2 A, c = 46.9 A. The asymmetric unit contains one PvuIIR dimer. Diffraction extends to 2.3 A, so the crystals may permit structural determination at atomic resolution.
J Mol Biol 1991 Dec 05
PMID:Purification, crystallization and preliminary X-ray diffraction studies of the PvuII endonuclease. 174 88

IS112 is a transposable element identified in Streptomyces albus G by its frequent mutagenic insertion into the genes for the SalI restriction-modification system. IS112 is present in several copies in the genome of S. albus G. Homologous sequences were detected in other Streptomyces strains. Sequence analysis revealed that IS112 has a length of 883 bp with a GC content of 67.4%. The copy that was isolated contained imperfect inverted repeats (16/20 match) at its ends and was flanked by a 2 bp duplication at the target site, which was located within the gene (salIR) for the SalI endonuclease. A long open reading frame (ORF) encoding a putative polypeptide of 256-253 amino acids spans almost the entire sequence. Significant homology was detected between this polypeptide and that corresponding to ORFB of IS493, an insertion sequence recently isolated from Streptomyces lividans 66.
Mol Gen Genet 1991 Jan
PMID:Isolation and genetic structure of IS112, an insertion sequence responsible for the inactivation of the SalI restriction-modification system of Streptomyces albus G. 184 88

The NgoPII restriction endonuclease, which recognizes the sequence 5'-GG decreases CC-3', differs from its isoschizomer HaeIII in being sensitive to methylation at the external cytosine residue. The entire nucleotide sequence of a cloned 3.3 kb segment of Neisseria gonorrhoeae strain P9 chromosomal DNA which harbours the NgoPII restriction-modification system has been determined. This data, coupled with sub-cloning experiments, indicates that the restriction endonuclease (R.NgoII) and modification (M.NgoII) genes are transcribed from separate promoters but are arranged in tandem, with the R.NgoPII gene being located on the 5' side of the M.NgoPII gene. Unlike all previously reported restriction systems the 3' end of the endonuclease open reading frame overlaps the 5' end of the methylase open reading frame by 8 codons. This overlap may have implications for the regulation of the NgoPII restriction-modification system.
Mol Gen Genet 1989 Apr
PMID:Nucleotide sequence and genetic organization of the NgoPII restriction-modification system of Neisseria gonorrhoeae. 250 49

The EcoP15 modification methylase gene from the p15B plasmid of Escherichia coli 15T-has been cloned and expressed at high levels in a plasmid vector system. We have purified the enzyme to near homogeneity in large amounts and have studied some of its enzymatic properties. Initial rates of methyl transfer are first order in methylase concentration and, with pUC19 DNA as substrate, the reaction proceeds by a random mechanism in which either DNA or S-adenosylmethionine can bind to the free enzyme. After methyltransfer to DNA, the methylated DNA and S-adenosylhomocysteine appear to dissociate in random order. As expected in such a mechanism, S-adenosylhomocysteine is a non-competitive inhibitor by S-adenosylmethionine at concentrations not much above its KM suggests that release of methylated DNA may be the rate-limiting step. This suggestion is strengthened by the fact that a mutant of the closely related EcoP1 does not show such substrate inhibition.
J Mol Biol 1989 Oct 20
PMID:Cloning, over-expression and the catalytic properties of the EcoP15 modification methylase from Escherichia coli. 258 3

The genes, encoding the restriction endonuclease and modification methylase EcoRV have been cloned from the natural plasmid pLG13 into pBR32 derivative vector pIL233. A resultant clone, expressing both enzyme activities, was used as a source of DNA for sequencing these genes by a procedure, that employed construction of deletion derivatives used to locate borders (by means of a functional test) and to sequence ca. 300 bp near the deletion breakpoint. From the sequence data, we infer that the endonuclease, a 29 KDa protein, and the methylase, a 36 KDa protein, are transcribed from a 310 bp intergenic region in opposite directions. There is no apparent homology between the enzymes and genes of the EcoRI and the EcoRV systems. A synthetic decamer, containing the EcoRV endonuclease recognition sequence and a phosphoamide bond at the cleavage point, is not cleaved by the highly purified endonuclease; the unmodified synthetic decamer is cleaved at the same conditions, only that the cleavage occurs to produce a blunt end--GAT/ATC, and not in a place previously reported (GATAT/C).
Mol Biol (Mosk)
PMID:[A system of EcoRV restriction-modification: genes, enzymes and synthetic substrates]. 298 49

Strain 1485IN and its derivatives were found to have a large inversion extending to about 35% of the chromosome. Because of this, the question arose as to whether 1485IN had arisen from an Escherichia coli strain other than K12. However, 1485IN had a flagellar antigen and a restriction-modification system indistinguishable from those of W3110, a major line of K12, and had retained an amber suppressor and lambda sensitivity that are characteristics of W1485 from which this strain seems to have arisen. Strain 1485IN had acquired proline auxotrophy, but showed the same growth rate as W1485 in nutrient broth at 37 degrees C. Interrupted matings with Hfr strains of 1485IN revealed a gene arrangement of nalA-gal-trp-his-lac-proA-thrleu-ilv, in which gal, trp, and his were on the inverted segment. The termini of the inversion were inferred to be situated between tsx (9.5 min) and purE (12 min) and between his (44 min) and cdd (46.5 min).
Mol Gen Genet 1986 Nov
PMID:A naturally occurring large chromosomal inversion in Escherichia coli K12. 354 22

The genes for restriction-modification system EcoRII have been cloned from plasmid N3 DNA using RSF2124 as a vector plasmid. The hybrid plasmids designated pFK321 and pFK322 contained a 5.8 megadaltons EcoRI--fragment derived from N3 DNA including the genes for restriction-modification system EcoRII and a gene for resistance to sulfanilamide.
Mol Gen Genet 1980
PMID:Molecular cloning of EcoRII endonuclease and methylase genes. 624 37

We have purified the type III restriction enzymes EcoP1 and EcoP15 to homogeneity from bacteria that contain the structural genes for the enzymes cloned on small, multicopy plasmids and which overproduce the enzymes. Both of the enzymes contain two different subunits. The molecular weights of the subunits are the same for both enzymes and antibodies prepared against one enzyme cross-react with both subunits of the other. Bacteria containing a plasmid derivative in which a large part of one of the structural genes has been deleted have a restriction- modification+ phenotype and contain only the smaller of the two subunits. This subunit therefore must be the one that both recognizes the specific DNA sequence and methylates it in the modification reaction (the restriction enzyme itself also acts as a modification methylase). We have purified the P1 and P15 modification subunits from these deletion derivatives and have shown that in vitro they have the expected properties: they are sequence-specific modification methylases. In addition, we have demonstrated that strains carrying the full restriction/modification system also contain a pool of free modification subunits that might be responsible for in vivo modification.
J Mol Biol 1983 Mar 25
PMID:DNA restriction--modification enzymes of phage P1 and plasmid p15B. Subunit functions and structural homologies. 630 81


1 2 3 4 5 Next >>