Structural determinants of human APOBEC3A enzymatic and nucleic acid binding properties
| Autor: | Kathryn Hinchee-Rodriguez, Kamil Hercík, Judith G. Levin, Chang-Hyeock Byeon, Lisa M. Charlton, Gabriel Nam, Angela M. Gronenborn, Mithun Mitra, Gisela Heidecker, In-Ja L. Byeon, Jinwoo Ahn, Dustin Singer, Shawn Hill |
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| Rok vydání: | 2013 |
| Předmět: |
Transcription
Genetic Protein Conformation Molecular Sequence Data DNA Single-Stranded Plasma protein binding Biology 03 medical and health sciences chemistry.chemical_compound Cytidine Deaminase Genetics Humans Amino Acid Sequence Amino Acids APOBEC3A Molecular Biology 030304 developmental biology 0303 health sciences Oligonucleotide Escherichia coli Proteins 030302 biochemistry & molecular biology Mutagenesis Proteins RNA Cytidine deaminase HIV Reverse Transcriptase 3. Good health DNA-Binding Proteins Long Interspersed Nucleotide Elements chemistry Biochemistry Deamination Mutation Nucleic acid Sequence Alignment DNA Protein Binding |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 0305-1048 |
| Popis: | Human APOBEC3A (A3A) is a single-domain cytidine deaminase that converts deoxycytidine residues to deoxyuridine in single-stranded DNA (ssDNA). It inhibits a wide range of viruses and endogenous retroelements such as LINE-1, but it can also edit genomic DNA, which may play a role in carcinogenesis. Here, we extend our recent findings on the NMR structure of A3A and report structural, biochemical and cell-based mutagenesis studies to further characterize A3A’s deaminase and nucleic acid binding activities. We find that A3A binds ssRNA, but the RNA and DNA binding interfaces differ and no deamination of ssRNA is detected. Surprisingly, with only one exception (G105A), alanine substitution mutants with changes in residues affected by specific ssDNA binding retain deaminase activity. Furthermore, A3A binds and deaminates ssDNA in a length-dependent manner. Using catalytically active and inactive A3A mutants, we show that the determinants of A3A deaminase activity and anti-LINE-1 activity are not the same. Finally, we demonstrate A3A’s potential to mutate genomic DNA during transient strand separation and show that this process could be counteracted by ssDNA binding proteins. Taken together, our studies provide new insights into the molecular properties of A3A and its role in multiple cellular and antiviral functions. |
| Databáze: | OpenAIRE |
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