Download MendeleyTetramerization at Low pH Licenses DNA Methylation Activity of M.HpyAXI in the Presence of Acid Stress.
Narayanan, N., Banerjee, A., Jain, D., Kulkarni, D.S., Sharma, R., Nirwal, S., Rao, D.N., Nair, D.T.(2020) J Mol Biol 432: 324-342
- PubMed: 31628946
- DOI: https://doi.org/10.1016/j.jmb.2019.10.001
- Primary Citation of Related Structures:
6K0W - PubMed Abstract:
Methylation of genomic DNA can influence the transcription profile of an organism and may generate phenotypic diversity for rapid adaptation in a dynamic environment. M.HpyAXI is a Type III DNA methyltransferase present in Helicobacter pylori and is upregulated at low pH. This enzyme may alter the expression of critical genes to ensure the survival of this pathogen at low pH inside the human stomach. M.HpyAXI methylates the adenine in the target sequence (5'-GCAG-3') and shows maximal activity at pH 5.5. Type III DNA methyltransferases are found to form an inverted dimer in the functional form. We observe that M.HpyAXI forms a nonfunctional dimer at pH 8.0 that is incapable of DNA binding and methylation activity. However, at pH 5.5, two such dimers associate to form a tetramer that now includes two functional dimers that can bind and methylate the target DNA sequence. Overall, we observe that the pH-dependent tetramerization of M.HpyAXI ensures that the enzyme is licensed to act only in the presence of acid stress.
Organizational Affiliation:
Laboratory of Genomic Integrity & Evolution, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India; Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
