Tetramerization at Low pH Licenses DNA Methylation Activity of M.HpyAXI in the Presence of Acid Stress

Narayanan, N and Banerjee, A and Jain, D and Kulkarni, DS and Sharma, R and Nirwal, S and Rao, DN and Nair, DT (2020) Tetramerization at Low pH Licenses DNA Methylation Activity of M.HpyAXI in the Presence of Acid Stress. In: Journal of Molecular Biology, 432 (2). pp. 324-342.

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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. © 2019 Elsevier Ltd

Item Type:	Journal Article
Publication:	Journal of Molecular Biology
Publisher:	Academic Press
Additional Information:	The copyright for this article belongs to Academic Press.
Keywords:	adenine; DNA methyltransferase; DNA methyltransferase III; genomic DNA; protein M.HpyAXI; sinefungin; unclassified drug; acid; adenine; DNA binding protein; site specific DNA methyltransferase (adenine specific), acidity; Article; chemical reaction; circular dichroism; complex formation; controlled study; DNA methylation; DNA sequence; enzyme activity; enzyme analysis; enzyme structure; nonhuman; photon correlation spectroscopy; priority journal; protein DNA binding; tetramerization; X ray diffraction; amino acid sequence; chemistry; DNA methylation; enzyme specificity; enzymology; genetics; Helicobacter infection; Helicobacter pylori; human; kinetics; metabolism; microbiology; pathogenicity; pH; physiological stress; protein multimerization, Acids; Adenine; Amino Acid Sequence; DNA Methylation; DNA-Binding Proteins; Helicobacter Infections; Helicobacter pylori; Humans; Hydrogen-Ion Concentration; Kinetics; Protein Multimerization; Site-Specific DNA-Methyltransferase (Adenine-Specific); Stress, Physiological; Substrate Specificity
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	06 Feb 2023 09:53
Last Modified:	06 Feb 2023 09:53
URI:	https://eprints.iisc.ac.in/id/eprint/79928

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