1
|
Clement PC, Sapam T, Nair DT. A conserved polar residue plays a critical role in mismatch detection in A-family DNA polymerases. Int J Biol Macromol 2024; 269:131965. [PMID: 38697428 DOI: 10.1016/j.ijbiomac.2024.131965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/26/2024] [Accepted: 04/27/2024] [Indexed: 05/05/2024]
Abstract
In A-family DNA polymerases (dPols), a functional 3'-5' exonuclease activity is known to proofread newly synthesized DNA. The identification of a mismatch in substrate DNA leads to transfer of the primer strand from the polymerase active site to the exonuclease active site. To shed more light regarding the mechanism responsible for the detection of mismatches, we have utilized DNA polymerase 1 from Aquifex pyrophilus (ApPol1). The enzyme synthesized DNA with high fidelity and exhibited maximal exonuclease activity with DNA substrates bearing mismatches at the -2 and - 3 positions. The crystal structure of apo-ApPol1 was utilized to generate a computational model of the functional ternary complex of this enzyme. The analysis of the model showed that N332 forms interactions with minor groove atoms of the base pairs at the -2 and - 3 positions. The majority of known A-family dPols show the presence of Asn at a position equivalent to N332. The N332L mutation led to a decrease in the exonuclease activity for representative purine-pyrimidine, and pyrimidine-pyrimidine mismatches at -2 and - 3 positions, respectively. Overall, our findings suggest that conserved polar residues located towards the minor groove may facilitate the detection of position-specific mismatches to enhance the fidelity of DNA synthesis.
Collapse
Affiliation(s)
- Patterson C Clement
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121 001, Haryana (NCR Delhi), India
| | - Tuleshwori Sapam
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121 001, Haryana (NCR Delhi), India
| | - Deepak T Nair
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121 001, Haryana (NCR Delhi), India.
| |
Collapse
|
2
|
Gao S, Guan H, Bloomer H, Wich D, Song D, Khirallah J, Ye Z, Zhao Y, Chen M, Xu C, Liu L, Xu Q. Harnessing non-Watson-Crick's base pairing to enhance CRISPR effectors cleavage activities and enable gene editing in mammalian cells. Proc Natl Acad Sci U S A 2024; 121:e2308415120. [PMID: 38150477 PMCID: PMC10786293 DOI: 10.1073/pnas.2308415120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 11/21/2023] [Indexed: 12/29/2023] Open
Abstract
Genomic DNA of the cyanophage S-2L virus is composed of 2-aminoadenine (Z), thymine (T), guanine (G), and cytosine (C), forming the genetic alphabet ZTGC, which violates Watson-Crick base pairing rules. The Z-base has an extra amino group on the two position that allows the formation of a third hydrogen bond with thymine in DNA strands. Here, we explored and expanded applications of this non-Watson-Crick base pairing in protein expression and gene editing. Both ZTGC-DNA (Z-DNA) and ZUGC-RNA (Z-RNA) produced in vitro show detectable compatibility and can be decoded in mammalian cells, including Homo sapiens cells. Z-crRNA can guide CRISPR-effectors SpCas9 and LbCas12a to cleave specific DNA through non-Watson-Crick base pairing and boost cleavage activities compared to A-crRNA. Z-crRNA can also allow for efficient gene and base editing in human cells. Together, our results help pave the way for potential strategies for optimizing DNA or RNA payloads for gene editing therapeutics and give insights to understanding the natural Z-DNA genome.
Collapse
Affiliation(s)
- Shuliang Gao
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Huiwen Guan
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Hanan Bloomer
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Douglas Wich
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Donghui Song
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Jennifer Khirallah
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Zhongfeng Ye
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Yu Zhao
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Mengting Chen
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Chutian Xu
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Lihan Liu
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Qiaobing Xu
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| |
Collapse
|
3
|
Yudkina AV, Endutkin AV, Diatlova EA, Zharkov DO. A non-canonical nucleotide from viral genomes interferes with the oxidative DNA damage repair system. DNA Repair (Amst) 2024; 133:103605. [PMID: 38042029 DOI: 10.1016/j.dnarep.2023.103605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/09/2023] [Accepted: 11/15/2023] [Indexed: 12/04/2023]
Abstract
Oxidative damage is a major source of genomic instability in all organisms with the aerobic metabolism. 8-Oxoguanine (8-oxoG), an abundant oxidized purine, is mutagenic and must be controlled by a dedicated DNA repair system (GO system) that prevents G:C→T:A transversions through an easily formed 8-oxoG:A mispair. In some forms, the GO system is present in nearly all cellular organisms. However, recent studies uncovered many instances of viruses possessing non-canonical nucleotides in their genomes. The features of genome damage and maintenance in such cases of alternative genetic chemistry remain barely explored. In particular, 2,6-diaminopurine (Z nucleotide) completely substitutes for A in the genomes of some bacteriophages, which have evolved pathways for dZTP synthesis and specialized polymerases that prefer dZTP over dATP. Here we address the ability of the GO system enzymes to cope with oxidative DNA damage in the presence of Z in DNA. DNA polymerases of two different structural families (Klenow fragment and RB69 polymerase) were able to incorporate dZMP opposite to 8-oxoG in the template, as well as 8-oxodGMP opposite to Z in the template. Fpg, a 8-oxoguanine-DNA glycosylase that discriminates against 8-oxoG:A mispairs, also did not remove 8-oxoG from 8-oxoG:Z mispairs. However, MutY, a DNA glycosylase that excises A from pairs with 8-oxoG, had a significantly lower activity on Z:8-oxoG mispairs. Similar preferences were observed for Fpg and MutY from different bacterial species (Escherichia coli, Staphylococcus aureus and Lactococcus lactis). Overall, the relaxed control of 8-oxoG in the presence of the Z nucleotide may be a source of additional mutagenesis in the genomes of bacteriophages or bacteria that have survived the viral invasion.
Collapse
Affiliation(s)
- Anna V Yudkina
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., Novosibirsk 630090, Russia; Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russia
| | - Anton V Endutkin
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., Novosibirsk 630090, Russia
| | - Evgeniia A Diatlova
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., Novosibirsk 630090, Russia
| | - Dmitry O Zharkov
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., Novosibirsk 630090, Russia; Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russia.
| |
Collapse
|
4
|
Czernecki D, Nourisson A, Legrand P, Delarue M. Reclassification of family A DNA polymerases reveals novel functional subfamilies and distinctive structural features. Nucleic Acids Res 2023; 51:4488-4507. [PMID: 37070157 PMCID: PMC10201439 DOI: 10.1093/nar/gkad242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 03/07/2023] [Accepted: 03/24/2023] [Indexed: 04/19/2023] Open
Abstract
Family A DNA polymerases (PolAs) form an important and well-studied class of extant polymerases participating in DNA replication and repair. Nonetheless, despite the characterization of multiple subfamilies in independent, dedicated works, their comprehensive classification thus far is missing. We therefore re-examine all presently available PolA sequences, converting their pairwise similarities into positions in Euclidean space, separating them into 19 major clusters. While 11 of them correspond to known subfamilies, eight had not been characterized before. For every group, we compile their general characteristics, examine their phylogenetic relationships and perform conservation analysis in the essential sequence motifs. While most subfamilies are linked to a particular domain of life (including phages), one subfamily appears in Bacteria, Archaea and Eukaryota. We also show that two new bacterial subfamilies contain functional enzymes. We use AlphaFold2 to generate high-confidence prediction models for all clusters lacking an experimentally determined structure. We identify new, conserved features involving structural alterations, ordered insertions and an apparent structural incorporation of a uracil-DNA glycosylase (UDG) domain. Finally, genetic and structural analyses of a subset of T7-like phages indicate a splitting of the 3'-5' exo and pol domains into two separate genes, observed in PolAs for the first time.
Collapse
Affiliation(s)
- Dariusz Czernecki
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unit of Architecture and Dynamics of Biological Macromolecules, 75015 Paris, France
- Sorbonne Université, Collège Doctoral, ED 515, 75005 Paris, France
| | - Antonin Nourisson
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unit of Architecture and Dynamics of Biological Macromolecules, 75015 Paris, France
- Sorbonne Université, Collège Doctoral, ED 515, 75005 Paris, France
| | - Pierre Legrand
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unit of Architecture and Dynamics of Biological Macromolecules, 75015 Paris, France
- Synchrotron SOLEIL, L’Orme des Merisiers, 91190 Saint-Aubin, France
| | - Marc Delarue
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unit of Architecture and Dynamics of Biological Macromolecules, 75015 Paris, France
| |
Collapse
|
5
|
Morcinek-Orłowska J, Zdrojewska K, Węgrzyn A. Bacteriophage-Encoded DNA Polymerases-Beyond the Traditional View of Polymerase Activities. Int J Mol Sci 2022; 23:635. [PMID: 35054821 PMCID: PMC8775771 DOI: 10.3390/ijms23020635] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/28/2021] [Accepted: 01/06/2022] [Indexed: 02/04/2023] Open
Abstract
DNA polymerases are enzymes capable of synthesizing DNA. They are involved in replication of genomes of all cellular organisms as well as in processes of DNA repair and genetic recombination. However, DNA polymerases can also be encoded by viruses, including bacteriophages, and such enzymes are involved in viral DNA replication. DNA synthesizing enzymes are grouped in several families according to their structures and functions. Nevertheless, there are examples of bacteriophage-encoded DNA polymerases which are significantly different from other known enzymes capable of catalyzing synthesis of DNA. These differences are both structural and functional, indicating a huge biodiversity of bacteriophages and specific properties of their enzymes which had to evolve under certain conditions, selecting unusual properties of the enzymes which are nonetheless crucial for survival of these viruses, propagating as special kinds of obligatory parasites. In this review, we present a brief overview on DNA polymerases, and then we discuss unusual properties of different bacteriophage-encoded enzymes, such as those able to initiate DNA synthesis using the protein-priming mechanisms or even start this process without any primer, as well as able to incorporate untypical nucleotides. Apart from being extremely interesting examples of biochemical biodiversity, bacteriophage-encoded DNA polymerases can also be useful tools in genetic engineering and biotechnology.
Collapse
Affiliation(s)
- Joanna Morcinek-Orłowska
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (J.M.-O.); (K.Z.)
| | - Karolina Zdrojewska
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (J.M.-O.); (K.Z.)
| | - Alicja Węgrzyn
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdansk, Poland
| |
Collapse
|
6
|
Kaminski PA. Mechanisms supporting aminoadenine-based viral DNA genomes. Cell Mol Life Sci 2021; 79:51. [PMID: 34910247 PMCID: PMC11072226 DOI: 10.1007/s00018-021-04055-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/17/2021] [Accepted: 11/21/2021] [Indexed: 10/19/2022]
Abstract
Bacteriophage genomes are the richest source of modified nucleobases of any life form. Of these, 2,6 diaminopurine, which pairs with thymine by forming three hydrogen bonds violates Watson and Crick's base pairing. 2,6 diaminopurine initially found in the cyanophage S-2L is more widespread than expected and has also been detected in phage infecting Gram-negative and Gram-positive bacteria. The biosynthetic pathway for aminoadenine containing DNA as well as the exclusion of adenine are now elucidated. This example of a natural deviation from the genetic code represents only one of the possibilities explored by nature and provides a proof of concept for the synthetic biology of non-canonical nucleic acids.
Collapse
Affiliation(s)
- P A Kaminski
- Biologie des Bactéries Pathogènes à Gram-Positif, Institut Pasteur, CNRS-UMR 2001, Paris, France.
| |
Collapse
|