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Identification and sequence analysis of a methylase gene in Porphyromonas gingivalis
J A Banas1, J J Ferretti, A Progulske-Fox
1Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City 73190.
Abstract:
A gene from the periodontal organism Porphyromonas gingivalis has been identified as encoding a DNA methylase. The gene, referred to as pgiIM, has been sequenced and found to contain a reading frame of 864 basepairs. The putative amino acid sequence of the encoded methylase was 288 amino acids, and shared 47% and 31% homology with the Streptococcus pneumoniae DpnII and E. coli Dam methylases, respectively. The activity and specificity of the pgi methylase (M.PgiI) was confirmed by cloning the gene into a dam- strain of E. coli (JM110) and performing a restriction analysis on the isolated DNA with enzymes whose activities depended upon the methylation state of the DNA. The data indicated that M.PgiI, like DpnII and Dam, methylated the adenine residue within the sequence 5'-GATC-3'.
Insights
Researchers identified a new DNA methylase gene, pgiIM, in Porphyromonas gingivalis. This enzyme, M.PgiI, methylates the 5'-GATC-3' sequence, similar to other known DNA methylases.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Porphyromonas gingivalis is a key pathogen in periodontal disease.
- DNA methylases play crucial roles in DNA replication, repair, and gene regulation.
- Understanding novel methylases can reveal new biological functions and therapeutic targets.
Purpose of the Study:
- To identify and characterize a novel DNA methylase from Porphyromonas gingivalis.
- To determine the DNA sequence and homology of the identified methylase gene.
- To confirm the enzymatic activity and DNA sequence specificity of the M.PgiI methylase.
Main Methods:
- Gene sequencing of the putative methylase gene (pgiIM) from P. gingivalis.
- Bioinformatic analysis to predict amino acid sequence and homology.
- Cloning of pgiIM into an E. coli dam- strain.
- Restriction analysis of methylated DNA using methylation-sensitive enzymes.
Main Results:
- The pgiIM gene was sequenced, encoding a 288-amino acid methylase (M.PgiI).
- M.PgiI showed homology to Streptococcus pneumoniae DpnII (47%) and E. coli Dam (31%) methylases.
- Functional analysis confirmed M.PgiI methylates adenine within the 5 omino-GATC-3 omino sequence.
Conclusions:
- A novel DNA methylase, M.PgiI, has been identified and characterized from Porphyromonas gingivalis.
- M.PgiI exhibits sequence specificity similar to DpnII and Dam methylases.
- This finding contributes to the understanding of epigenetic modifications in oral bacteria.