Complete genome sequences of two closely related cellular organisms became available for the first time for two Helicobacter pylori strains [1,4]. Their comparison at single base pair level suggested presence of a novel mechanism for gene mobility — insertion with long target duplication [3]. It is formally similar to transposon insertion, but the duplication is much longer (often in the range ...

conclusions based on this similarity and our bioinformatics evaluations, this mentioned alpha-amylase gene can be expressed in s. cerevisiae as extracellular enzyme. results the presence of alpha-amylase gene in recombinant bacteria was certificated by colony-pcr method. after extraction of recombinant vector from e. coli, the competent s. cerevisiae cells were transformed using polyethylene gl...

avian adenovirus was isolated from naturally infected birds during 1990 to 2003 in the vicinity ofkarachi, pakistan. the virus is known to cause hydro-pericardium syndrome (hps) in poultry. the mortalitywas recorded 20-50% in commercial broilers. fifty field samples were collected; however, six samples wereselected for molecular studies. these isolates were grown and characterized by cell cultu...

INTRODUCTION Incubation of a blunt-end ligation reaction in the presence of an excess amount of an appropriate restriction enzyme can dramatically increase the yield of recombinant plasmids. The role of the restriction enzyme is to cleave circular and linear concatemers at restriction sites that are re-formed when linear, blunt-ended plasmid molecules ligate to themselves. In almost all cases, ...

Restriction mapping involves cleaving DNA clones at specific sites with enzymes to produce a set of fragments. These fragments have characteristic lengths which together constitute a multiset (a set allowing repeated elements) called the “fingerprint” of the clone. Clones that overlap with each other share common restriction fragments as long as the region of overlap contains at least two enzym...

An enzyme was isolated from a eucaryotic, Chlorella-like green alga infected with the virus PBCV-1 which exhibits type II restriction endonuclease activity. The enzyme recognized the sequence GATC and cleaved DNA 5' to the G. Methylation of deoxyadenosine in the GATC sequence inhibited enzyme activity. In vitro the enzyme cleaved host Chlorella nuclear DNA but not viral DNA because host DNA con...

The restriction endonuclease from Escherichia coli K specifically cleaves foreign DNA in the presence of S-adenosylmethionine, ATP, and Mg2+. The role of S-adenosylmethionine in this reaction has been studied by following the specific binding of the enzyme to unmodified DNA. The results indicate that S-adenosylmethionine acts as an allosteric effector. However, the rate-limiting step in the act...

background: aspergillus species are associated with allergic bronchopulmonary disease, mycotic keratitis, otomycosis, na­sal sinusitis and invasive infection. in this study, we developed a pcr-single strand confomational polymorphism method to identify the most common aspergillus species and we showed some advantages of this method comparing a pcr-restric­tion fragment length polymorphism with ...