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51.
J. E. Tomilova V. V. Kuznetsov M. A. Abdurashitov N. A. Netesova S. Kh. Degtyarev 《Molecular Biology》2010,44(4):606-615
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 λ. Highly purified enzyme has been isolated by chromatography on various resins from Escherichia coli cells where it is accumulated in a soluble form. The study of M1.Bst19I properties has revealed that the enzyme has a temperature
optimum at 50°C and demonstrates maximal 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 λ DNA is 0.68 ± 0.07 μM, Km for S-adenosyl-L-methionine is 2.02 ± 0.31 μM. Catalytical constant (k
cat) is 1.8 ± 0.05 min−1. Comparative analysis of Target Recognition Domain amino acid sequences for M1.Bst19I and other α-N6-DNA-methyltransferases
has allowed us to suggest the presence of two types of the enzymes containing ATG or ATC triplets in the recognition sequence. 相似文献
52.
Tomilova Yu. E. Abdurashitov M. A. Golikova L. N. Netesova N. A. Degtyarev S. Kh. 《Molecular Biology》2004,38(6):850-856
The Streptococcus faecalis ND547 and Bacillus stearothermophilus 19 genes that code for DNA methyltransferases (MTases, M.) of restriction–modification (RM) systems with the same recognition sequence, 5-GCATC-3 were cloned and sequenced. The Bst19I RM system includes two MTases, M1.Bst19I and M2.Bst19I. The SfaNI RM system has only one MTase, M.SfaNI, whose N and C domains are homologous to M2.Bst19I and M1.Bst19I, respectively. Both M1.Bst19I and M2.Bst19I and the two domains of M.SfaNI contain conserved elements, which are arranged in the order characteristic of class N6-adenine MTases. The enzymes of the SfaNI and Bst19I RM systems proved to be highly homologous to their FokI and BstF5I counterparts, which was explained by the presence of the common tetranucleotide 5-GATG-3 in their recognition sites. Based on sequence homology, the spatial arrangement of highly conserved amino acid residues was determined using the known three-dimensional model of M.DpnIIA, which belongs to the same MTase class. 相似文献
53.
Chernukhin VA Golikova LN Gonchar DA Abdurashitov MA Kashirina YG Netesova NA Degtyarev SKh 《Biochemistry. Biokhimii?a》2003,68(9):967-975
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. We estimated the principal kinetic parameters of the reaction of transfer of methyl group from the donor S-adenosyl-L-methionine to the recognition site 5"-CATCC-3" catalyzed by BstF5I-2 and BstF5I-4 DNA [N6-adenine]-methyl-transferases from the BstF5I restriction–modification system. 相似文献
54.
Golikova L. N. Gutorov V. V. Evdokimov A. A. Shchelkunov S. N. Gonchar D. A. Okhapkina S. S. Degtyarev S. Kh. Netesova N. A. 《Russian Journal of Bioorganic Chemistry》2002,28(1):77-79
The fourth DNA-methyltransferase of the BstF5I restriction–modification (RM) system from Bacillus stearothermophilus F5 (M.BstF5I-4) was discovered, which modifies the adenine residue within the upper strand of the recognition site 5"-GGATG-3"/5"-CATCC-3". Thus, unlike other known RM systems, the BstF5I RM system comprises four genes encoding DNA-methyltransferases, three of which possess the same substrate specificity and methylate adenine within the 5"-GGATG sequence. 相似文献
55.
Golikova LN Guturov VV Evdokimov AA Shchelkunov SN Gonchar DA Okhapkina SS Degtiarev SKh Netesova NA 《Bioorganicheskaia khimiia》2002,28(1):84-86
The fourth DNA-methyltransferase of the BstF5I restriction-modification (RM) system from Bacillus stearothermophilus F5 (M.BstF5I-4) was discovered, which modifies the adenine residue within the upper strand of the recognition site 5'-GGATG-3'/5'-CATCC-3'. Thus, unlike other known RM systems, the BstF5I RM system comprises four genes encoding DNA-methyltransferases, three of which possess the same substrate specificity and methylate adenine within the 5'-GGATG sequence. The English version of the paper. 相似文献
56.
HELÉNA RAGONÉ 《American anthropologist》2004,106(1):176-177
Experiencing the New Genetics: Family and Kinship on the Medical Frontier. Kaja Finkler. Philadelphia: University of Pennsylvania Press, 2000. 296 pp.
Born and Bred: Idioms and New Reproductive Technologies in England. Jeanette Edwards. New York: Oxford University Press, 2000. 264 pp. 相似文献
Born and Bred: Idioms and New Reproductive Technologies in England. Jeanette Edwards. New York: Oxford University Press, 2000. 264 pp. 相似文献
57.
58.
Gene and domain duplication in the chordate Otx gene family: insights from amphioxus Otx 总被引:6,自引:1,他引:5
We report the genomic organization and deduced protein sequence of a
cephalochordate member of the Otx homeobox gene family (AmphiOtx) and show
its probable single-copy state in the genome. We also present molecular
phylogenetic analysis indicating that there was single ancestral Otx gene
in the first chordates which was duplicated in the vertebrate lineage after
it had split from the lineage leading to the cephalochordates. Duplication
of a C-terminal protein domain has occurred specifically in the vertebrate
lineage, strengthening the case for a single Otx gene in an ancestral
chordate whose gene structure has been retained in an extant
cephalochordate. Comparative analysis of protein sequences and published
gene expression patterns suggest that the ancestral chordate Otx gene had
roles in patterning the anterior mesendoderm and central nervous system.
These roles were elaborated following Otx gene duplication in vertebrates,
accompanied by regulatory and structural divergence, particularly of Otx1
descendant genes.
相似文献
59.
60.