DNA_Modifying_Enzymes_Presentation.pptks
- 1. DNA Modifying Enzymes: Modification Enzymes Understanding Types, Mechanisms, and Applications
- 2. Introduction to DNA Modifying Enzymes • - Enzymes that alter DNA sequences or structures. • - Categories: • 1. Restriction enzymes (cut DNA) • 2. Modification enzymes (alter DNA bases) • - Importance: Essential tools in molecular biology and biotechnology.
- 3. Overview of Modification Enzymes • - Definition: Enzymes that chemically modify DNA bases to protect or regulate gene expression. • - Types: • - DNA methyltransferases • - Base-flipping enzymes • - Glycosyltransferases
- 4. DNA Methyltransferases • - Function: Add methyl groups to DNA (e.g., 5- methylcytosine). • - Mechanism: • 1. Recognize specific DNA sequences. • 2. Transfer a methyl group from S-adenosyl methionine (SAM) to DNA. • - Examples: • - Dam methylase: Adds methyl groups to adenine in GATC sequences.
- 5. Biological Functions of DNA Methylation • - Gene expression regulation (epigenetic silencing). • - Protection against restriction enzymes in bacteria. • - Role in development and disease (e.g., cancer).
- 6. Other DNA Modifying Enzymes • - Glycosyltransferases: Add sugars to DNA or RNA. • - Base Flipping Enzymes: Alter the base-pairing properties of nucleotides. • - Deaminases: Convert one base into another (e.g., cytosine to uracil).
- 7. Applications in Biotechnology • - Epigenetic research and studies on gene regulation. • - Development of methylation-specific PCR assays. • - Tools for gene editing (e.g., base editing via CRISPR-Cas9). • - Restriction-modification systems in cloning.
- 8. Experimental Tools • - Assays for DNA methylation: • - Bisulfite sequencing. • - Methylation-sensitive restriction enzymes. • - Inhibitors of modification enzymes: • - 5-Azacytidine (targets DNA methyltransferases).
- 9. Conclusion • - DNA modification enzymes are crucial for regulating genetic information. • - Play roles in natural biological systems and modern biotechnology. • - Future potential: Enhanced tools for epigenetics and genome editing.
- 10. References • - Molecular Biology of the Cell by Alberts et al. • - Relevant research papers and articles.