In neoplastic cells, levels of DNA methyltransferase activity are often increased, and evidence is accruing to suggest an important role for this event in tumorigenesis. To evaluate this possibility further, and to investigate the contribution of increasing de novo, as opposed to maintenance, DNA methylation in mammalian cells, we expressed the bacterial HhaI methyltransferase in cultured murin...

This chapter describes a method for the rapid assessment of promoter hypermethylation levels or methylation of imprinted regions in human genomic DNA extracted from various sources using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA). Multiplex ligation-dependent probe amplification (MLPA) is a powerful and easy-to-perform PCR-based technique that can identify g...

4'-Thio-2'-deoxycytidine was synthesized as a 5'- protected phosphoramidite compatible with solid phase DNA synthesis. When incorporated as the target cytosine (C*) in the GC*GC recognition sequence for the DNA methyltransferase M. HhaI, methyl transfer was strongly inhibited. In contrast, these same oligonucleotides were normal substrates for the cognate restriction endonuclease R. HhaI and it...

The DNA fingerprint profiles and somatic serotypes of 71 Pasteurella multocida capsule serogroup B isolates, 13 capsule serogroup E isolates, and 16 somatic reference serotype strains were compared. Each of the 16 reference somatic serotypes had a unique DNA fingerprint profile with the HhaI restriction endonuclease. Fifty-four serogroup B isolates (isolated from classical cases of hemorrhagic ...

HhaI DNA methyltransferase belongs to the C5-cytosine methyltransferase family, which is characterized by the presence of a set of highly conserved amino acids and motifs present in an invariant order. HhaI DNA methyltransferase has been subjected to a lot of biochemical and crystallographic studies. A number of issues, especially the role of the conserved amino acids in the methyltransferase a...

Background: Hemophilia B is an X-linked recessive coagulation disorder caused by factor IX deficiency. Analysis of factor IX gene polymorphisms is considered the best approach for prenatal diagnosis and carrier detection of hemophilia B where the identification of gene mutation is not easily possible. Objective: To study the frequency of three factor IX-linked restriction fragment length polymo...

Background: Hemophilia B is an X-linked recessive coagulation disorder caused by factor IX deficiency.  Analysis of factor IX gene polymorphisms is considered the best approach for prenatal diagnosis and carrier detection of hemophilia B where the identification of gene mutation is not easily possible. Objective: To study the frequency of three factor IX-linked restriction fragment length polym...

A system for addressing in the construction of macromolecular assemblies can be based on the biospecificity of DNA (cytosine-5) methyltransferases and the capacity of these enzymes to form abortive covalent complexes at targeted 5-fluorocytosine residues in DNA. Using this system, macromolecular assemblies have been created using two representative methyltransferases: M-HhaI and M x MspI. When ...

background: hemophilia b is an x-linked recessive coagulation disorder caused by factor ix deficiency.  analysis of factor ix gene polymorphisms is considered the best approach for prenatal diagnosis and carrier detection of hemophilia b where the identification of gene mutation is not easily possible.   objective: to study the frequency of three factor ix-linked restriction fragment length pol...