Cloning and Characterization of a New Site-Specific Methyl-Directed ElmI Endonuclease Recognizing and Cleaving C5-methylated DNA Sequence 5'-G(5mC)^NG(5mC)-3'.

Putative open reading frames of MD-endonucleases have been identified in Enterobacteria genomes as a result of the search for amino acid sequences homologous to MD-endonuclease BisI. A highly conserved DNA primary structure of these open reading frames in different genera of Enterobacteria (Escherichia, Klebsiella and Cronobacter) has allowed researchers to create primers for PCR screening, which was carried out on Enterobacteria DNA collected from natural sources. The DNA fragment, about 440 bp in length, was amplified by use of the genomic DNA of a wild E.

Medium-sized tandem repeats represent an abundant component of the Drosophila virilis genome.

Background: Previously, we developed a simple method for carrying out a restriction enzyme analysis of eukaryotic DNA in silico, based on the known DNA sequences of the genomes. This method allows the user to calculate lengths of all DNA fragments that are formed after a whole genome is digested at the theoretical recognition sites of a given restriction enzyme. A comparison of the observed peaks in distribution diagrams with the results from DNA cleavage using several restriction enzymes performed in vitro have shown good correspondence between the theoretical and experimental data in several cases.

Substrate specificity and biochemical properties of M3.BstF5I DNA methyltransferase from the BstF5I restriction-modification system.

Optimal conditions for DNA methylation by the M3.BstF5I enzyme from Bacillus stearothermophilus and kinetic parameters of lambda phage DNA modification and that of a number of oligonucleotide substrates are established. Comparison of M1.

GlaI digestion of mouse gamma-satellite DNA: study of primary structure and ACGT sites methylation.

Background: Patterns of mouse DNA hydrolysis with restriction enzymes are coincided with calculated diagrams of genomic DNA digestion in silico, except presence of additional bright bands, which correspond to monomer and dimer of gamma-satellite DNA. Only small portion of mouse gamma-satellite DNA sequences are presented in databases. Methyl-directed endonuclease GlaI cleaves mouse DNA and may be useful for a detailed study of primary structure and CG dinucleotides methylation in gamma-satellite DNA.

[Purification of recombinant DNA methyltransferase M2.BstSE from nickase-modification system NM.BstSEI and study of the enzyme properties].

The operon of nickase-modification system from Bacillus stearothermophilus SE-589 (recognition site 5'-GAGTC-3') includes two DNA methyltransferase genes: bstSEIM1 and bstSEIM2. Gene encoding DNA methyltransferase M2.BstSEI was cloned in pJW vector and expressed in E.

A physical map of human Alu repeats cleavage by restriction endonucleases.

Background: Alu repetitive elements are the abundant sequences in human genome. Diversity of DNA sequences of these elements makes difficult the construction of theoretical patterns of Alu repeats cleavage by restriction endonucleases. We have proposed a method of restriction analysis of Alu repeats sequences in silico.

Isolation and characterization of biochemical properties of DNA methyltransferase FauIA modifying the second cytosine in the nonpalindromic sequence 5'-CCCGC-3'.

A gene encoding DNA methyltransferase (methylase) FauIA of the restriction-modification system FauI from Flavobacterium aquatile (recognizing sequence 5'-CCCGC-3') was cloned in pJW vector. The latter was used for transformation of E. coli RRI cells followed by subsequent thermoinduction and biomass elaboration.

M.BstF5I-2 and M.BstF5I-4 DNA methyltransferases from BstF5I restriction-modification system of Bacillus stearothermophilus F5.

The BstF5I restriction-modification system from Bacillus stearothermophilus F5 includes four site-specific DNA methyltransferases, thus differing from all known restriction-modification systems. Here we demonstrated for the first time that one bacterial cell can possess two pairs of methylases with identical substrate specificities (methylases BstF5I-1 and BstF5I-3 recognize GGATG, whereas methylases BstF5I-2 and BstF5I-4 recognize CATCC) that modify adenine residues on both DNA strands. Different chromatographic methods provide homogenous preparations of methylases BstF5I-2 and BstF5I-4.

Nonlinear relationships in the patterns of neuronal spiking in cortical neurons.

The pattern of neuronal spiking of cortical neurons was investigated in an awake nonimmobilized rabbit. Thecharacteristics of the interspike intervals (total numberof intervals, mean interval, mean-square deviation) and of the burst (group) activity (burst number, mean spikefrequency in a burst, mean spike number for a burst, meanburst duration) were considered. Nonlinear relationshipbetween the values of mean interspike intervals and thenumber of spike bursts was found.

[Cytogenetic analysis of insertions into drosophila interband polytene chromosomes].

Using the method of P-element-mediated enhancer detection, 29 Drosophila melanogaster lines were obtained that carried P-1ArB vector insertions in chromosomes 2 and 3. The expression of the reporter gene lacZ at different developmental stages of the transformed lines was determined in color reactions for beta-galactosidase. Regions of vector integration were located using in situ hybridization.