Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.1.1.37 (DNA methyltransferase)
 4,983 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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).
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PMID:[A system of EcoRV restriction-modification: genes, enzymes and synthetic substrates]. 298 49

The M1.Bst19I DNA-methyltransferase gene from restriction-modification system Bst19I (recognition sequence 5'-GCATC-3') in Bacillus stearothermophilus 19 has been cloned in the expressing vector pJW, that carries a tandem of thermo inducible promoters P(R)/P(L) from phage lambda. Highly purified enzyme has been isolated by chromatography on various resins from E. coli cells where it accumulates in a soluble form. Study of M1.Bst19I properties has revealed that enzyme has a temperature optimum 50 degrees C and demonstrates the maximum activity at pH 8.0. M1.Bst19I modifies adenine in sequence 5'-GCATC-3'. Kinetic parameters of M1.Bst19I DNA methylation reaction have been determined as follows: Km for lambda DNA is 0.68 +/- 0.07 microM, Km for S-adenosil-L-methionine is 2.02 +/- 0.31 microM. Catalytical constant (kcat) is 1.8 +/- 0.05 min(-1). Comparative analysis of Target Recognition Domain amino acid sequences for M1.Bst19I and others alpha-N6-DNA methyltransferases has allowed to suppose a presence of two types of the enzymes containing a triplet ATG or ATC in the recognition sequence.
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PMID:[Recombinant DNA-methyltransferase M1.Bst19I from Bacillus stearothermophilus 19: purification, propeties and amino acids sequence analysis]. 2087 29