Journal of Bacteriology & Parasitology

Distinctive properties of a membrane-associated nuclease of Mycoplasma meleagridis

3^rd International Congress on Bacteriology and Infectious Diseases

August 04-06, 2015 Valencia, Spain

Boutheina Ben Abdelmoumen Mardassi and Elhem Yacoub

Posters-Accepted Abstracts: J Bacteriol Parasitol

Abstract:

The nuclease activity of mycoplasmas is an important factor in their pathogenicity. Nucleases may produce a broad
spectrum of biological effects in hosts. In the present study, the ability of Mycoplasma meleagridis for nuclease synthesis
was reported. Nuclease activity was found to be associated with a membrane protein named Mm19. BLASTP search analysis
revealed a significant sequence similarity with a type II restriction enzyme belonging to the RE_AlwI super family. Further, Bioinformational
analysis allowed the identification of a DNA methyl transferase which together with restriction enzymes forms
restriction-modification (R-M) systems offering bacteria an effective defense system against foreign DNAs. Two sequences
encoding for an endo nuclease of the RE_AlwI super family and for its DNA methyl transferaseare found juxstaposed and
oppositely oriented in Mycoplasma meleagridis genome sequence. Like most of type II restriction enzymes, Mm19-associated
nuclease activity was enhanced with Mg2+. Mm19 showed significant homologies with AlwI related sequences in other
mycoplasmas (Mycoplasma mycoides subsp. capri GM12 and Mycoplasma bovis PG45) and other bacterial species such as
Streptococcus, Bacillus and Staphylococcus. Based on sequence alignments, the 714-aa methylase sequence was found to harbor
two putative conserved domains differently organized compared to other mycoplasmas methylases domains. In fact, these two
putative conserved domains were found to be located in the same CDS in Mycoplasma meleagridis methylase while they were
disjointed in two separated CDSs in other mycoplasmas methylases. The Mycoplasma meleagridis Mm19 encoded-product
might be involved in pathogenicity and in the survival of this mycoplasma in the host.

Biography :

Boutheina Ben Abdelmoumen Mardassi is a Doctorate in Veterinary Medicine from National School of Veterinary Medicine at Sidi Thabet, Tunis-Tunisia. She has
completed her PhD from Biotechnology Research Institute at Montreal (BRI) and Montreal University in Canada. She was Post Doctorate from Armand-Frappier
Institute at Montreal, Quebec, Canada. Since 2000, she is a Permanent Researcher and a Head of Mycoplasmas Laboratory at Pasteur Institute of Tunis. She has
published more than 15 papers in avian and human scientific journals.