1
|
Balu KE, Tang Q, Almohdar D, Ratcliffe J, Kalaycioğlu M, Çağlayan M. Structures of LIG1 uncover the mechanism of sugar discrimination against 5'-RNA-DNA junctions during ribonucleotide excision repair. J Biol Chem 2024:107688. [PMID: 39159820 DOI: 10.1016/j.jbc.2024.107688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 08/06/2024] [Accepted: 08/07/2024] [Indexed: 08/21/2024] Open
Abstract
Ribonucleotides in DNA cause several types of genome instability and can be removed by ribonucleotide excision repair (RER) that is finalized by DNA ligase 1 (LIG1). However, the mechanism by which LIG1 discriminates the RER intermediate containing a 5'-RNA-DNA lesion generated by RNase H2-mediated cleavage of ribonucleotides remains unknown. Here, we determine X-ray structures of LIG1/5'-rG:C at the initial step of ligation where AMP is bound to the active site of the ligase, and uncover a large conformational change downstream the nick resulting in a shift at Arg(R)871 residue in the Adenylation domain of the ligase. Furthermore, we demonstrate a diminished ligation of the nick DNA substrate with a 5'-ribonucleotide in comparison to an efficient end joining of the nick substrate with a 3'-ribonucleotide by LIG1. Finally, our results demonstrate that mutations at the active site residues of the ligase and LIG1 disease-associated variants significantly impact the ligation efficiency of RNA-DNA heteroduplexes harboring "wrong" sugar at 3'- or 5'-end of nick. Collectively, our findings provide a novel atomic insight into proficient sugar discrimination by LIG1 during processing of the most abundant form of DNA damage in cells, genomic ribonucleotides, during initial step of the RER pathway.
Collapse
Affiliation(s)
- Kanal Elamparithi Balu
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
| | - Qun Tang
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
| | - Danah Almohdar
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
| | - Jacob Ratcliffe
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
| | - Mustafa Kalaycioğlu
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
| | - Melike Çağlayan
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA.
| |
Collapse
|
2
|
Balu KE, Gulkis M, Almohdar D, Çağlayan M. Structures of LIG1 provide a mechanistic basis for understanding a lack of sugar discrimination against a ribonucleotide at the 3'-end of nick DNA. J Biol Chem 2024; 300:107216. [PMID: 38522520 PMCID: PMC11035063 DOI: 10.1016/j.jbc.2024.107216] [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: 12/28/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 03/26/2024] Open
Abstract
Human DNA ligase 1 (LIG1) is the main replicative ligase that seals Okazaki fragments during nuclear replication and finalizes DNA repair pathways by joining DNA ends of the broken strand breaks in the three steps of the ligation reaction. LIG1 can tolerate the RNA strand upstream of the nick, yet an atomic insight into the sugar discrimination mechanism by LIG1 against a ribonucleotide at the 3'-terminus of nick DNA is unknown. Here, we determined X-ray structures of LIG1/3'-RNA-DNA hybrids and captured the ligase during pre- and post-step 3 the ligation reaction. Furthermore, the overlays of 3'-rA:T and 3'-rG:C step 3 structures with step 2 structures of canonical 3'-dA:T and 3'-dG:C uncover a network of LIG1/DNA interactions through Asp570 and Arg871 side chains with 2'-OH of the ribose at nick showing a final phosphodiester bond formation and the other ligase active site residues surrounding the AMP site. Finally, we demonstrated that LIG1 can ligate the nick DNA substrates with pre-inserted 3'-ribonucleotides as efficiently as Watson-Crick base-paired ends in vitro. Together, our findings uncover a novel atomic insight into a lack of sugar discrimination by LIG1 and the impact of improper sugar on the nick sealing of ribonucleotides at the last step of DNA replication and repair.
Collapse
Affiliation(s)
- Kanal Elamparithi Balu
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
| | - Mitchell Gulkis
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
| | - Danah Almohdar
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
| | - Melike Çağlayan
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA.
| |
Collapse
|
3
|
Kaminski AM, Chiruvella KK, Ramsden DA, Bebenek K, Kunkel TA, Pedersen LC. DNA polymerase λ Loop1 variant yields unexpected gain-of-function capabilities in nonhomologous end-joining. DNA Repair (Amst) 2024; 136:103645. [PMID: 38428373 PMCID: PMC11078337 DOI: 10.1016/j.dnarep.2024.103645] [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: 11/29/2023] [Revised: 01/26/2024] [Accepted: 01/31/2024] [Indexed: 03/03/2024]
Abstract
DNA polymerases lambda (Polλ) and mu (Polμ) are X-Family polymerases that participate in DNA double-strand break (DSB) repair by the nonhomologous end-joining pathway (NHEJ). Both polymerases direct synthesis from one DSB end, using template derived from a second DSB end. In this way, they promote the NHEJ ligation step and minimize the sequence loss normally associated with this pathway. The two polymerases differ in cognate substrate, as Polλ is preferred when synthesis must be primed from a base-paired DSB end, while Polμ is required when synthesis must be primed from an unpaired DSB end. We generated a Polλ variant (PolλKGET) that retained canonical Polλ activity on a paired end-albeit with reduced incorporation fidelity. We recently discovered that the variant had unexpectedly acquired the activity previously unique to Polμ-synthesis from an unpaired primer terminus. Though the sidechains of the Loop1 region make no contact with the DNA substrate, PolλKGET Loop1 amino acid sequence is surprisingly essential for its unique activity during NHEJ. Taken together, these results underscore that the Loop1 region plays distinct roles in different Family X polymerases.
Collapse
Affiliation(s)
- Andrea M Kaminski
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg 101, Research Triangle Park, NC 27709, USA
| | - Kishore K Chiruvella
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Katarzyna Bebenek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg 101, Research Triangle Park, NC 27709, USA
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg 101, Research Triangle Park, NC 27709, USA
| | - Lars C Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg 101, Research Triangle Park, NC 27709, USA.
| |
Collapse
|
4
|
Kuznetsova AA, Senchurova SI, Gavrilova AA, Tyugashev TE, Mikushina ES, Kuznetsov NA. Substrate Specificity Diversity of Human Terminal Deoxynucleotidyltransferase May Be a Naturally Programmed Feature Facilitating Its Biological Function. Int J Mol Sci 2024; 25:879. [PMID: 38255952 PMCID: PMC10815903 DOI: 10.3390/ijms25020879] [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: 11/30/2023] [Revised: 01/04/2024] [Accepted: 01/04/2024] [Indexed: 01/24/2024] Open
Abstract
Terminal 2'-deoxynucleotidyl transferase (TdT) is a unique enzyme capable of catalysing template-independent elongation of DNA 3' ends during V(D)J recombination. The mechanism controlling the enzyme's substrate specificity, which is necessary for its biological function, remains unknown. Accordingly, in this work, kinetic and mutational analyses of human TdT were performed and allowed to determine quantitative characteristics of individual stages of the enzyme-substrate interaction, which overall may ensure the enzyme's operation either in the distributive or processive mode of primer extension. It was found that conformational dynamics of TdT play an important role in the formation of the catalytic complex. Meanwhile, the nature of the nitrogenous base significantly affected both the dNTP-binding and catalytic-reaction efficiency. The results indicated that neutralisation of the charge and an increase in the internal volume of the active site caused a substantial increase in the activity of the enzyme and induced a transition to the processive mode in the presence of Mg2+ ions. Surrogate metal ions Co2+ or Mn2+ also may regulate the switching of the enzymatic process to the processive mode. Thus, the totality of individual factors affecting the activity of TdT ensures effective execution of its biological function.
Collapse
Affiliation(s)
- Aleksandra A. Kuznetsova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), 8 Prospekt Akad. Lavrentyeva, Novosibirsk 630090, Russia; (A.A.K.); (S.I.S.); (A.A.G.); (T.E.T.)
| | - Svetlana I. Senchurova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), 8 Prospekt Akad. Lavrentyeva, Novosibirsk 630090, Russia; (A.A.K.); (S.I.S.); (A.A.G.); (T.E.T.)
| | - Anastasia A. Gavrilova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), 8 Prospekt Akad. Lavrentyeva, Novosibirsk 630090, Russia; (A.A.K.); (S.I.S.); (A.A.G.); (T.E.T.)
| | - Timofey E. Tyugashev
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), 8 Prospekt Akad. Lavrentyeva, Novosibirsk 630090, Russia; (A.A.K.); (S.I.S.); (A.A.G.); (T.E.T.)
| | - Elena S. Mikushina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), 8 Prospekt Akad. Lavrentyeva, Novosibirsk 630090, Russia; (A.A.K.); (S.I.S.); (A.A.G.); (T.E.T.)
| | - Nikita A. Kuznetsov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), 8 Prospekt Akad. Lavrentyeva, Novosibirsk 630090, Russia; (A.A.K.); (S.I.S.); (A.A.G.); (T.E.T.)
- Department of Natural Sciences, Novosibirsk State University, 2 Pirogova Str., Novosibirsk 630090, Russia
| |
Collapse
|
5
|
Parkash V, Kulkarni Y, Bylund GO, Osterman P, Kamerlin S, Johansson E. A sensor complements the steric gate when DNA polymerase ϵ discriminates ribonucleotides. Nucleic Acids Res 2023; 51:11225-11238. [PMID: 37819038 PMCID: PMC10639073 DOI: 10.1093/nar/gkad817] [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: 07/01/2023] [Revised: 09/01/2023] [Accepted: 09/20/2023] [Indexed: 10/13/2023] Open
Abstract
The cellular imbalance between high concentrations of ribonucleotides (NTPs) and low concentrations of deoxyribonucleotides (dNTPs), is challenging for DNA polymerases when building DNA from dNTPs. It is currently believed that DNA polymerases discriminate against NTPs through a steric gate model involving a clash between a tyrosine and the 2'-hydroxyl of the ribonucleotide in the polymerase active site in B-family DNA polymerases. With the help of crystal structures of a B-family polymerase with a UTP or CTP in the active site, molecular dynamics simulations, biochemical assays and yeast genetics, we have identified a mechanism by which the finger domain of the polymerase sense NTPs in the polymerase active site. In contrast to the previously proposed polar filter, our experiments suggest that the amino acid residue in the finger domain senses ribonucleotides by steric hindrance. Furthermore, our results demonstrate that the steric gate in the palm domain and the sensor in the finger domain are both important when discriminating NTPs. Structural comparisons reveal that the sensor residue is conserved among B-family polymerases and we hypothesize that a sensor in the finger domain should be considered in all types of DNA polymerases.
Collapse
Affiliation(s)
- Vimal Parkash
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå 90187, Sweden
| | - Yashraj Kulkarni
- Department of Chemistry - BMC, Uppsala University, Box 576, Uppsala S-751 23, Sweden
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Göran O Bylund
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå 90187, Sweden
| | - Pia Osterman
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå 90187, Sweden
| | - Shina Caroline Lynn Kamerlin
- Department of Chemistry - BMC, Uppsala University, Box 576, Uppsala S-751 23, Sweden
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332-0400, USA
| | - Erik Johansson
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå 90187, Sweden
| |
Collapse
|
6
|
Primer terminal ribonucleotide alters the active site dynamics of DNA polymerase η and reduces DNA synthesis fidelity. J Biol Chem 2023; 299:102938. [PMID: 36702254 PMCID: PMC9976465 DOI: 10.1016/j.jbc.2023.102938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/25/2023] Open
Abstract
DNA polymerases catalyze DNA synthesis with high efficiency, which is essential for all life. Extensive kinetic and structural efforts have been executed in exploring mechanisms of DNA polymerases, surrounding their kinetic pathway, catalytic mechanisms, and factors that dictate polymerase fidelity. Recent time-resolved crystallography studies on DNA polymerase η (Pol η) and β have revealed essential transient events during the DNA synthesis reaction, such as mechanisms of primer deprotonation, separated roles of the three metal ions, and conformational changes that disfavor incorporation of the incorrect substrate. DNA-embedded ribonucleotides (rNs) are the most common lesion on DNA and a major threat to genome integrity. While kinetics of rN incorporation has been explored and structural studies have revealed that DNA polymerases have a steric gate that destabilizes ribonucleotide triphosphate binding, the mechanism of extension upon rN addition remains poorly characterized. Using steady-state kinetics, static and time-resolved X-ray crystallography with Pol η as a model system, we showed that the extra hydroxyl group on the primer terminus does alter the dynamics of the polymerase active site as well as the catalysis and fidelity of DNA synthesis. During rN extension, Pol η error incorporation efficiency increases significantly across different sequence contexts. Finally, our systematic structural studies suggest that the rN at the primer end improves primer alignment and reduces barriers in C2'-endo to C3'-endo sugar conformational change. Overall, our work provides further mechanistic insights into the effects of rN incorporation on DNA synthesis.
Collapse
|
7
|
Polλ promotes microhomology-mediated end-joining. Nat Struct Mol Biol 2023; 30:107-114. [PMID: 36536104 DOI: 10.1038/s41594-022-00895-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 11/04/2022] [Indexed: 12/24/2022]
Abstract
The double-strand break (DSB) repair pathway called microhomology-mediated end-joining (MMEJ) is thought to be dependent on DNA polymerase theta (Polθ) and occur independently of nonhomologous end-joining (NHEJ) factors. An unresolved question is whether MMEJ is facilitated by a single Polθ-mediated end-joining pathway or consists of additional undiscovered pathways. We find that human X-family Polλ, which functions in NHEJ, additionally exhibits robust MMEJ activity like Polθ. Polλ promotes MMEJ in mammalian cells independently of essential NHEJ factors LIG4/XRCC4 and Polθ, which reveals a distinct Polλ-dependent MMEJ mechanism. X-ray crystallography employing in situ photo-induced DSB formation captured Polλ in the act of stabilizing a microhomology-mediated DNA synapse with incoming nucleotide at 2.0 Å resolution and reveals how Polλ performs replication across a DNA synapse joined by minimal base-pairing. Last, we find that Polλ is semisynthetic lethal with BRCA1 and BRCA2. Together, these studies indicate Polλ MMEJ as a distinct DSB repair mechanism.
Collapse
|
8
|
Kaminski AM, Chiruvella KK, Ramsden DA, Bebenek K, Kunkel TA, Pedersen LC. Analysis of diverse double-strand break synapsis with Polλ reveals basis for unique substrate specificity in nonhomologous end-joining. Nat Commun 2022; 13:3806. [PMID: 35778389 PMCID: PMC9249759 DOI: 10.1038/s41467-022-31278-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 06/10/2022] [Indexed: 01/02/2023] Open
Abstract
DNA double-strand breaks (DSBs) threaten genomic stability, since their persistence can lead to loss of critical genetic information, chromosomal translocations or rearrangements, and cell death. DSBs can be repaired through the nonhomologous end-joining pathway (NHEJ), which processes and ligates DNA ends efficiently to prevent or minimize sequence loss. Polymerase λ (Polλ), one of the Family X polymerases, fills sequence gaps of DSB substrates with a strict specificity for a base-paired primer terminus. There is little information regarding Polλ's approach to engaging such substrates. We used in vitro polymerization and cell-based NHEJ assays to explore the contributions of conserved loop regions toward DSB substrate specificity and utilization. In addition, we present multiple crystal structures of Polλ in synapsis with varying biologically relevant DSB end configurations, revealing how key structural features and hydrogen bonding networks work in concert to stabilize these tenuous, potentially cytotoxic DNA lesions during NHEJ.
Collapse
Affiliation(s)
- Andrea M Kaminski
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101, Research Triangle Park, NC, 27709, USA
| | - Kishore K Chiruvella
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Katarzyna Bebenek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101, Research Triangle Park, NC, 27709, USA.
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101, Research Triangle Park, NC, 27709, USA
| | - Lars C Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Dr., Bldg. 101, Research Triangle Park, NC, 27709, USA
| |
Collapse
|
9
|
Jamsen JA, Shock DD, Wilson SH. Watching right and wrong nucleotide insertion captures hidden polymerase fidelity checkpoints. Nat Commun 2022; 13:3193. [PMID: 35680862 PMCID: PMC9184648 DOI: 10.1038/s41467-022-30141-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/19/2022] [Indexed: 12/26/2022] Open
Abstract
Efficient and accurate DNA synthesis is enabled by DNA polymerase fidelity checkpoints that promote insertion of the right instead of wrong nucleotide. Erroneous X-family polymerase (pol) λ nucleotide insertion leads to genomic instability in double strand break and base-excision repair. Here, time-lapse crystallography captures intermediate catalytic states of pol λ undergoing right and wrong natural nucleotide insertion. The revealed nucleotide sensing mechanism responds to base pair geometry through active site deformation to regulate global polymerase-substrate complex alignment in support of distinct optimal (right) or suboptimal (wrong) reaction pathways. An induced fit during wrong but not right insertion, and associated metal, substrate, side chain and pyrophosphate reaction dynamics modulated nucleotide insertion. A third active site metal hastened right but not wrong insertion and was not essential for DNA synthesis. The previously hidden fidelity checkpoints uncovered reveal fundamental strategies of polymerase DNA repair synthesis in genomic instability. DNA polymerase (pol) λ performs DNA synthesis in base excision and double strand break repair. How pol λ accomplishes nucleotide insertion that can lead to mutagenesis and genomic instability was unclear. Here the authors employ time-lapse crystallography to reveal hidden polymerase checkpoints that enable right and wrong natural nucleotide insertion by pol λ.
Collapse
Affiliation(s)
- Joonas A Jamsen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
| | - David D Shock
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
| |
Collapse
|
10
|
Weaver TM, Click TH, Khoang TH, Todd Washington M, Agarwal PK, Freudenthal BD. Mechanism of nucleotide discrimination by the translesion synthesis polymerase Rev1. Nat Commun 2022; 13:2876. [PMID: 35610266 PMCID: PMC9130138 DOI: 10.1038/s41467-022-30577-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 05/06/2022] [Indexed: 11/09/2022] Open
Abstract
Rev1 is a translesion DNA synthesis (TLS) polymerase involved in the bypass of adducted-guanine bases and abasic sites during DNA replication. During damage bypass, Rev1 utilizes a protein-template mechanism of DNA synthesis, where the templating DNA base is evicted from the Rev1 active site and replaced by an arginine side chain that preferentially binds incoming dCTP. Here, we utilize X-ray crystallography and molecular dynamics simulations to obtain structural insight into the dCTP specificity of Rev1. We show the Rev1 R324 protein-template forms sub-optimal hydrogen bonds with incoming dTTP, dGTP, and dATP that prevents Rev1 from adopting a catalytically competent conformation. Additionally, we show the Rev1 R324 protein-template forms optimal hydrogen bonds with incoming rCTP. However, the incoming rCTP adopts an altered sugar pucker, which prevents the formation of a catalytically competent Rev1 active site. This work provides novel insight into the mechanisms for nucleotide discrimination by the TLS polymerase Rev1.
Collapse
Affiliation(s)
- Tyler M Weaver
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA.,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA
| | - Timothy H Click
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State University, Stillwater, Oklahoma, 74048, USA
| | - Thu H Khoang
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA.,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA
| | - M Todd Washington
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, 52242, USA
| | - Pratul K Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State University, Stillwater, Oklahoma, 74048, USA.
| | - Bret D Freudenthal
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA. .,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA.
| |
Collapse
|
11
|
Jamsen JA, Sassa A, Perera L, Shock DD, Beard WA, Wilson SH. Structural basis for proficient oxidized ribonucleotide insertion in double strand break repair. Nat Commun 2021; 12:5055. [PMID: 34417448 PMCID: PMC8379156 DOI: 10.1038/s41467-021-24486-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 05/11/2021] [Indexed: 01/09/2023] Open
Abstract
Reactive oxygen species (ROS) oxidize cellular nucleotide pools and cause double strand breaks (DSBs). Non-homologous end-joining (NHEJ) attaches broken chromosomal ends together in mammalian cells. Ribonucleotide insertion by DNA polymerase (pol) μ prepares breaks for end-joining and this is required for successful NHEJ in vivo. We previously showed that pol μ lacks discrimination against oxidized dGTP (8-oxo-dGTP), that can lead to mutagenesis, cancer, aging and human disease. Here we reveal the structural basis for proficient oxidized ribonucleotide (8-oxo-rGTP) incorporation during DSB repair by pol μ. Time-lapse crystallography snapshots of structural intermediates during nucleotide insertion along with computational simulations reveal substrate, metal and side chain dynamics, that allow oxidized ribonucleotides to escape polymerase discrimination checkpoints. Abundant nucleotide pools, combined with inefficient sanitization and repair, implicate pol μ mediated oxidized ribonucleotide insertion as an emerging source of widespread persistent mutagenesis and genomic instability.
Collapse
Affiliation(s)
- Joonas A Jamsen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA.
| | - Akira Sassa
- Laboratory of Chromatin Metabolism and Epigenetics, Graduate School of Science, Chiba University, Chiba, Japan
| | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - David D Shock
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - William A Beard
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA.
| |
Collapse
|
12
|
Ohashi S, Hashiya F, Abe H. Variety of Nucleotide Polymerase Mutants Aiming to Synthesize Modified RNA. Chembiochem 2021; 22:2398-2406. [PMID: 33822453 DOI: 10.1002/cbic.202100004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/01/2021] [Indexed: 01/09/2023]
Abstract
Significant efforts have been made to develop therapeutic RNA aptamers that exploit synthetic RNA to capture target molecules. However, ensuring RNA aptamers are resistant against intrinsic nucleases remains an issue and restricts their use as therapeutics. Introduction of chemical modifications to the 2' sugar moiety of RNA improves their stability effectively and can be achieved by chemical synthesis using modified phosphoramidites; however, this approach is not suitable for preparing long RNA molecules. Although recombinant nucleotide polymerases can transcribe RNA, these polymerases cannot synthesize modified RNA because they do not recognize 2' modified nucleoside triphosphates. In this review, we focus on several polymerase mutants that tolerate substrates containing modifications of the 2' sugar moiety to synthesize RNA, and the problems that must be overcome to prepare chemically modified RNA with high efficacy by in vitro transcription.
Collapse
Affiliation(s)
- Sana Ohashi
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
| | - Fumitaka Hashiya
- Research Center for Material Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
| | - Hiroshi Abe
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
- Research Center for Material Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
- CREST, Japan Science and Technology Agency, 7, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan
- Institute for Glyco-core Research (iGCORE), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
| |
Collapse
|
13
|
Ghosh D, Raghavan SC. 20 years of DNA Polymerase μ, the polymerase that still surprises. FEBS J 2021; 288:7230-7242. [DOI: 10.1111/febs.15852] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 03/02/2021] [Accepted: 03/01/2021] [Indexed: 12/22/2022]
Affiliation(s)
- Dipayan Ghosh
- Department of Biochemistry Indian Institute of Science Bangalore India
| | | |
Collapse
|
14
|
Kaminski AM, Bebenek K, Pedersen LC, Kunkel TA. DNA polymerase mu: An inflexible scaffold for substrate flexibility. DNA Repair (Amst) 2021; 93:102932. [PMID: 33087269 DOI: 10.1016/j.dnarep.2020.102932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
DNA polymerase μ is a Family X member that participates in repair of DNA double strand breaks (DSBs) by non-homologous end joining. Its role is to fill short gaps arising as intermediates in the process of V(D)J recombination and during processing of accidental double strand breaks. Pol μ is the only known template-dependent polymerase that can repair non-complementary DSBs with unpaired 3´primer termini. Here we review the unique properties of Pol μ that allow it to productively engage such a highly unstable substrate to generate a nick that can be sealed by DNA Ligase IV.
Collapse
Affiliation(s)
- Andrea M Kaminski
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Katarzyna Bebenek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Lars C Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
| |
Collapse
|
15
|
The PHP domain of PolX from Staphylococcus aureus aids high fidelity DNA synthesis through the removal of misincorporated deoxyribo-, ribo- and oxidized nucleotides. Sci Rep 2021; 11:4178. [PMID: 33603016 PMCID: PMC7893174 DOI: 10.1038/s41598-021-83498-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 01/27/2021] [Indexed: 01/31/2023] Open
Abstract
The X family is one of the eight families of DNA polymerases (dPols) and members of this family are known to participate in the later stages of Base Excision Repair. Many prokaryotic members of this family possess a Polymerase and Histidinol Phosphatase (PHP) domain at their C-termini. The PHP domain has been shown to possess 3'-5' exonuclease activity and may represent the proofreading function in these dPols. PolX from Staphylococcus aureus also possesses the PHP domain at the C-terminus, and we show that this domain has an intrinsic Mn2+ dependent 3'-5' exonuclease capable of removing misincorporated dNMPs from the primer. The misincorporation of oxidized nucleotides such as 8oxodGTP and rNTPs are known to be pro-mutagenic and can lead to genomic instability. Here, we show that the PHP domain aids DNA replication by the removal of misincorporated oxidized nucleotides and rNMPs. Overall, our study shows that the proofreading activity of the PHP domain plays a critical role in maintaining genomic integrity and stability. The exonuclease activity of this enzyme can, therefore, be the target of therapeutic intervention to combat infection by methicillin-resistant-Staphylococcus-aureus.
Collapse
|
16
|
El-Sayed WMM, Gombolay AL, Xu P, Yang T, Jeon Y, Balachander S, Newnam G, Tao S, Bowen NE, Brůna T, Borodovsky M, Schinazi RF, Kim B, Chen Y, Storici F. Disproportionate presence of adenosine in mitochondrial and chloroplast DNA of Chlamydomonas reinhardtii. iScience 2020; 24:102005. [PMID: 33490913 PMCID: PMC7809514 DOI: 10.1016/j.isci.2020.102005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/29/2020] [Accepted: 12/23/2020] [Indexed: 11/02/2022] Open
Abstract
Ribonucleoside monophosphates (rNMPs) represent the most common non-standard nucleotides found in the genome of cells. The distribution of rNMPs in DNA has been studied only in limited genomes. Using the ribose-seq protocol and the Ribose-Map bioinformatics toolkit, we reveal the distribution of rNMPs incorporated into the whole genome of a photosynthetic unicellular green alga, Chlamydomonas reinhardtii. We discovered a disproportionate incorporation of adenosine in the mitochondrial and chloroplast DNA, in contrast to the nuclear DNA, relative to the corresponding nucleotide content of these C. reinhardtii organelle genomes. Our results demonstrate that the rNMP content in the DNA of the algal organelles reflects an elevated ATP level present in the algal cells. We reveal specific biases and patterns in rNMP distributions in the algal mitochondrial, chloroplast, and nuclear DNA. Moreover, we identified the C. reinhardtii orthologous genes for all three subunits of the RNase H2 enzyme using GeneMark-EP + gene finder.
Collapse
Affiliation(s)
- Waleed M M El-Sayed
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.,Marine Microbiology Department, National Institute of Oceanography and Fisheries, Red Sea, 84517, Egypt
| | - Alli L Gombolay
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Penghao Xu
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Taehwan Yang
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Youngkyu Jeon
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Sathya Balachander
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Gary Newnam
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Sijia Tao
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30309, USA
| | - Nicole E Bowen
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30309, USA
| | - Tomáš Brůna
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Mark Borodovsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.,Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Raymond F Schinazi
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30309, USA
| | - Baek Kim
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30309, USA
| | - Yongsheng Chen
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Francesca Storici
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| |
Collapse
|
17
|
Brissett NC, Zabrady K, Płociński P, Bianchi J, Korycka-Machała M, Brzostek A, Dziadek J, Doherty AJ. Molecular basis for DNA repair synthesis on short gaps by mycobacterial Primase-Polymerase C. Nat Commun 2020; 11:4196. [PMID: 32826907 PMCID: PMC7442782 DOI: 10.1038/s41467-020-18012-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 07/30/2020] [Indexed: 02/03/2023] Open
Abstract
Cells utilise specialized polymerases from the Primase-Polymerase (Prim-Pol) superfamily to maintain genome stability. Prim-Pol's function in genome maintenance pathways including replication, repair and damage tolerance. Mycobacteria contain multiple Prim-Pols required for lesion repair, including Prim-PolC that performs short gap repair synthesis during excision repair. To understand the molecular basis of Prim-PolC's gap recognition and synthesis activities, we elucidated crystal structures of pre- and post-catalytic complexes bound to gapped DNA substrates. These intermediates explain its binding preference for short gaps and reveal a distinctive modus operandi called Synthesis-dependent Template Displacement (STD). This mechanism enables Prim-PolC to couple primer extension with template base dislocation, ensuring that the unpaired templating bases in the gap are ushered into the active site in an ordered manner. Insights provided by these structures establishes the molecular basis of Prim-PolC's gap recognition and extension activities, while also illuminating the mechanisms of primer extension utilised by closely related Prim-Pols.
Collapse
Affiliation(s)
- Nigel C Brissett
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, BN1 9RQ, UK.,School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, BN2 4GJ, UK
| | - Katerina Zabrady
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, BN1 9RQ, UK
| | - Przemysław Płociński
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, BN1 9RQ, UK.,Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Lodz, Poland
| | - Julie Bianchi
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, BN1 9RQ, UK.,Department of Oncology-Pathology, BioClinicum, Karolinska University Hospital, Stockholm, Sweden
| | | | - Anna Brzostek
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Lodz, Poland
| | - Jarosław Dziadek
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Lodz, Poland
| | - Aidan J Doherty
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, BN1 9RQ, UK.
| |
Collapse
|
18
|
Ribonucleotide incorporation in yeast genomic DNA shows preference for cytosine and guanosine preceded by deoxyadenosine. Nat Commun 2020; 11:2447. [PMID: 32415081 PMCID: PMC7229183 DOI: 10.1038/s41467-020-16152-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 04/14/2020] [Indexed: 12/14/2022] Open
Abstract
Despite the abundance of ribonucleoside monophosphates (rNMPs) in DNA, sites of rNMP incorporation remain poorly characterized. Here, by using ribose-seq and Ribose-Map techniques, we built and analyzed high-throughput sequencing libraries of rNMPs derived from mitochondrial and nuclear DNA of budding and fission yeast. We reveal both common and unique features of rNMP sites among yeast species and strains, and between wild type and different ribonuclease H-mutant genotypes. We demonstrate that the rNMPs are not randomly incorporated in DNA. We highlight signatures and patterns of rNMPs, including sites within trinucleotide-repeat tracts. Our results uncover that the deoxyribonucleotide immediately upstream of the rNMPs has a strong influence on rNMP distribution, suggesting a mechanism of rNMP accommodation by DNA polymerases as a driving force of rNMP incorporation. Consistently, we find deoxyadenosine upstream from the most abundant genomic rCMPs and rGMPs. This study establishes a framework to better understand mechanisms of rNMP incorporation in DNA. Ribonucleoside monophosphates are incorporated by DNA polymerases into double-stranded DNA. Here, the authors use ribose-seq and Ribose-Map techniques to reveal that signatures and patterns of ribonucleotide incorporation in yeast mitochondrial and nuclear DNA show preference for cytosine and guanosine preceded by deoxyadenosine.
Collapse
|
19
|
Johnson MK, Kottur J, Nair DT. A polar filter in DNA polymerases prevents ribonucleotide incorporation. Nucleic Acids Res 2020; 47:10693-10705. [PMID: 31544946 PMCID: PMC6846668 DOI: 10.1093/nar/gkz792] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/02/2019] [Accepted: 09/09/2019] [Indexed: 12/17/2022] Open
Abstract
The presence of ribonucleotides in DNA can lead to genomic instability and cellular lethality. To prevent adventitious rNTP incorporation, the majority of the DNA polymerases (dPols) possess a steric filter. The dPol named MsDpo4 (Mycobacterium smegmatis) naturally lacks this steric filter and hence is capable of rNTP addition. The introduction of the steric filter in MsDpo4 did not result in complete abrogation of the ability of this enzyme to incorporate ribonucleotides. In comparison, DNA polymerase IV (PolIV) from Escherichia coli exhibited stringent selection for deoxyribonucleotides. A comparison of MsDpo4 and PolIV led to the discovery of an additional polar filter responsible for sugar selectivity. Thr43 represents the filter in PolIV and this residue forms interactions with the incoming nucleotide to draw it closer to the enzyme surface. As a result, the 2’-OH in rNTPs will clash with the enzyme surface, and therefore ribonucleotides cannot be accommodated in the active site in a conformation compatible with productive catalysis. The substitution of the equivalent residue in MsDpo4–Cys47, with Thr led to a drastic reduction in the ability of the mycobacterial enzyme to incorporate rNTPs. Overall, our studies evince that the polar filter serves to prevent ribonucleotide incorporation by dPols.
Collapse
Affiliation(s)
- Mary K Johnson
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, India.,National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore 560065, India
| | - Jithesh Kottur
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, India
| | - Deepak T Nair
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, India
| |
Collapse
|
20
|
Su Y, Ghodke PP, Egli M, Li L, Wang Y, Guengerich FP. Human DNA polymerase η has reverse transcriptase activity in cellular environments. J Biol Chem 2019; 294:6073-6081. [PMID: 30842261 DOI: 10.1074/jbc.ra119.007925] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/04/2019] [Indexed: 12/24/2022] Open
Abstract
Classical DNA and RNA polymerase (pol) enzymes have defined roles with their respective substrates, but several pols have been found to have multiple functions. We reported previously that purified human DNA pol η (hpol η) can incorporate both deoxyribonucleoside triphosphates (dNTPs) and ribonucleoside triphosphates (rNTPs) and can use both DNA and RNA as substrates. X-ray crystal structures revealed that two pol η residues, Phe-18 and Tyr-92, behave as steric gates to influence sugar selectivity. However, the physiological relevance of these phenomena has not been established. Here, we show that purified hpol η adds rNTPs to DNA primers at physiological rNTP concentrations and in the presence of competing dNTPs. When two rATPs were inserted opposite a cyclobutane pyrimidine dimer, the substrate was less efficiently cleaved by human RNase H2. Human XP-V fibroblast extracts, devoid of hpol η, could not add rNTPs to a DNA primer, but the expression of transfected hpol η in the cells restored this ability. XP-V cell extracts did not add dNTPs to DNA primers hybridized to RNA, but could when hpol η was expressed in the cells. HEK293T cell extracts could add dNTPs to DNA primers hybridized to RNA, but lost this ability if hpol η was deleted. Interestingly, a similar phenomenon was not observed when other translesion synthesis (TLS) DNA polymerases-hpol ι, κ, or ζ-were individually deleted. These results suggest that hpol η is one of the major reverse transcriptases involved in physiological processes in human cells.
Collapse
Affiliation(s)
- Yan Su
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Pratibha P Ghodke
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Martin Egli
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Lin Li
- Department of Chemistry, University of California, Riverside, Riverside, California 92521
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, Riverside, California 92521
| | - F Peter Guengerich
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146.
| |
Collapse
|
21
|
Pryor JM, Conlin MP, Carvajal-Garcia J, Luedeman ME, Luthman AJ, Small GW, Ramsden DA. Ribonucleotide incorporation enables repair of chromosome breaks by nonhomologous end joining. Science 2018; 361:1126-1129. [PMID: 30213916 PMCID: PMC6252249 DOI: 10.1126/science.aat2477] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/31/2018] [Accepted: 07/20/2018] [Indexed: 11/02/2022]
Abstract
The nonhomologous end-joining (NHEJ) pathway preserves genome stability by ligating the ends of broken chromosomes together. It employs end-processing enzymes, including polymerases, to prepare ends for ligation. We show that two such polymerases incorporate primarily ribonucleotides during NHEJ-an exception to the central dogma of molecular biology-both during repair of chromosome breaks made by Cas9 and during V(D)J recombination. Moreover, additions of ribonucleotides but not deoxynucleotides effectively promote ligation. Repair kinetics suggest that ribonucleotide-dependent first-strand ligation is followed by complementary strand repair with deoxynucleotides, then by replacement of ribonucleotides embedded in the first strand with deoxynucleotides. Our results indicate that as much as 65% of cellular NHEJ products have transiently embedded ribonucleotides, which promote flexibility in repair at the cost of more fragile intermediates.
Collapse
Affiliation(s)
- John M Pryor
- Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Michael P Conlin
- Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Juan Carvajal-Garcia
- Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Megan E Luedeman
- Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Adam J Luthman
- Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - George W Small
- Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Dale A Ramsden
- Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
| |
Collapse
|
22
|
Vaisman A, Woodgate R. Ribonucleotide discrimination by translesion synthesis DNA polymerases. Crit Rev Biochem Mol Biol 2018; 53:382-402. [PMID: 29972306 DOI: 10.1080/10409238.2018.1483889] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The well-being of all living organisms relies on the accurate duplication of their genomes. This is usually achieved by highly elaborate replicase complexes which ensure that this task is accomplished timely and efficiently. However, cells often must resort to the help of various additional "specialized" DNA polymerases that gain access to genomic DNA when replication fork progression is hindered. One such specialized polymerase family consists of the so-called "translesion synthesis" (TLS) polymerases; enzymes that have evolved to replicate damaged DNA. To fulfill their main cellular mission, TLS polymerases often must sacrifice precision when selecting nucleotide substrates. Low base-substitution fidelity is a well-documented inherent property of these enzymes. However, incorrect nucleotide substrates are not only those which do not comply with Watson-Crick base complementarity, but also those whose sugar moiety is incorrect. Does relaxed base-selectivity automatically mean that the TLS polymerases are unable to efficiently discriminate between ribonucleoside triphosphates and deoxyribonucleoside triphosphates that differ by only a single atom? Which strategies do TLS polymerases employ to select suitable nucleotide substrates? In this review, we will collate and summarize data accumulated over the past decade from biochemical and structural studies, which aim to answer these questions.
Collapse
Affiliation(s)
- Alexandra Vaisman
- a Laboratory of Genomic Integrity , National Institute of Child Health and Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Roger Woodgate
- a Laboratory of Genomic Integrity , National Institute of Child Health and Human Development, National Institutes of Health , Bethesda , MD , USA
| |
Collapse
|
23
|
Moon AF, Pryor JM, Ramsden DA, Kunkel TA, Bebenek K, Pedersen LC. Structural accommodation of ribonucleotide incorporation by the DNA repair enzyme polymerase Mu. Nucleic Acids Res 2017; 45:9138-9148. [PMID: 28911097 PMCID: PMC5587726 DOI: 10.1093/nar/gkx527] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 06/23/2017] [Indexed: 02/02/2023] Open
Abstract
While most DNA polymerases discriminate against ribonucleotide triphosphate (rNTP) incorporation very effectively, the Family X member DNA polymerase μ (Pol μ) incorporates rNTPs almost as efficiently as deoxyribonucleotides. To gain insight into how this occurs, here we have used X-ray crystallography to describe the structures of pre- and post-catalytic complexes of Pol μ with a ribonucleotide bound at the active site. These structures reveal that Pol μ binds and incorporates a rNTP with normal active site geometry and no distortion of the DNA substrate or nucleotide. Moreover, a comparison of rNTP incorporation kinetics by wildtype and mutant Pol μ indicates that rNTP accommodation involves synergistic interactions with multiple active site residues not found in polymerases with greater discrimination. Together, the results are consistent with the hypothesis that rNTP incorporation by Pol μ is advantageous in gap-filling synthesis during DNA double strand break repair by nonhomologous end joining, particularly in nonreplicating cells containing very low deoxyribonucleotide concentrations.
Collapse
Affiliation(s)
- Andrea F Moon
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - John M Pryor
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Katarzyna Bebenek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Lars C Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| |
Collapse
|
24
|
van Loon B, Hübscher U, Maga G. Living on the Edge: DNA Polymerase Lambda between Genome Stability and Mutagenesis. Chem Res Toxicol 2017; 30:1936-1941. [DOI: 10.1021/acs.chemrestox.7b00152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Barbara van Loon
- Department
of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Erling Skjalgssons gt 1, N-7491 Trondheim, Norway
- Department
of Pathology and Medical Genetics, St. Olavs Hospital, Trondheim University Hospital, 7491 Trondheim, Norway
| | - Ulrich Hübscher
- Department
of Molecular Mechanisms of Disease, University of Zürich, Winterthurerstrasse
190, CH-8057 Zürich, Switzerland
| | - Giovanni Maga
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| |
Collapse
|
25
|
Mentegari E, Crespan E, Bavagnoli L, Kissova M, Bertoletti F, Sabbioneda S, Imhof R, Sturla SJ, Nilforoushan A, Hübscher U, van Loon B, Maga G. Ribonucleotide incorporation by human DNA polymerase η impacts translesion synthesis and RNase H2 activity. Nucleic Acids Res 2017; 45:2600-2614. [PMID: 27994034 PMCID: PMC5389505 DOI: 10.1093/nar/gkw1275] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 12/07/2016] [Indexed: 12/25/2022] Open
Abstract
Ribonucleotides (rNs) incorporated in the genome by DNA polymerases (Pols) are removed by RNase H2. Cytidine and guanosine preferentially accumulate over the other rNs. Here we show that human Pol η can incorporate cytidine monophosphate (rCMP) opposite guanine, 8-oxo-7,8-dihydroguanine, 8-methyl-2΄-deoxyguanosine and a cisplatin intrastrand guanine crosslink (cis-PtGG), while it cannot bypass a 3-methylcytidine or an abasic site with rNs as substrates. Pol η is also capable of synthesizing polyribonucleotide chains, and its activity is enhanced by its auxiliary factor DNA Pol δ interacting protein 2 (PolDIP2). Human RNase H2 removes cytidine and guanosine less efficiently than the other rNs and incorporation of rCMP opposite DNA lesions further reduces the efficiency of RNase H2. Experiments with XP-V cell extracts indicate Pol η as the major basis of rCMP incorporation opposite cis-PtGG. These results suggest that translesion synthesis by Pol η can contribute to the accumulation of rCMP in the genome, particularly opposite modified guanines.
Collapse
Affiliation(s)
- Elisa Mentegari
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Emmanuele Crespan
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Laura Bavagnoli
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Miroslava Kissova
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Federica Bertoletti
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Simone Sabbioneda
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Ralph Imhof
- Department of Molecular Mechanisms of Disease, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Shana J Sturla
- Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, CH-8092 Zürich, Switzerland
| | - Arman Nilforoushan
- Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, CH-8092 Zürich, Switzerland
| | - Ulrich Hübscher
- Department of Molecular Mechanisms of Disease, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Barbara van Loon
- Department of Molecular Mechanisms of Disease, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Giovanni Maga
- DNA Enzymology & Molecular Virology and Cell Nucleus & DNA replication Units, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| |
Collapse
|
26
|
Antoniali G, Malfatti MC, Tell G. Unveiling the non-repair face of the Base Excision Repair pathway in RNA processing: A missing link between DNA repair and gene expression? DNA Repair (Amst) 2017. [DOI: 10.1016/j.dnarep.2017.06.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
27
|
Mentegari E, Kissova M, Bavagnoli L, Maga G, Crespan E. DNA Polymerases λ and β: The Double-Edged Swords of DNA Repair. Genes (Basel) 2016; 7:genes7090057. [PMID: 27589807 PMCID: PMC5042388 DOI: 10.3390/genes7090057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/30/2016] [Accepted: 08/24/2016] [Indexed: 12/28/2022] Open
Abstract
DNA is constantly exposed to both endogenous and exogenous damages. More than 10,000 DNA modifications are induced every day in each cell's genome. Maintenance of the integrity of the genome is accomplished by several DNA repair systems. The core enzymes for these pathways are the DNA polymerases. Out of 17 DNA polymerases present in a mammalian cell, at least 13 are specifically devoted to DNA repair and are often acting in different pathways. DNA polymerases β and λ are involved in base excision repair of modified DNA bases and translesion synthesis past DNA lesions. Polymerase λ also participates in non-homologous end joining of DNA double-strand breaks. However, recent data have revealed that, depending on their relative levels, the cell cycle phase, the ratio between deoxy- and ribo-nucleotide pools and the interaction with particular auxiliary proteins, the repair reactions carried out by these enzymes can be an important source of genetic instability, owing to repair mistakes. This review summarizes the most recent results on the ambivalent properties of these enzymes in limiting or promoting genetic instability in mammalian cells, as well as their potential use as targets for anticancer chemotherapy.
Collapse
Affiliation(s)
- Elisa Mentegari
- Institute of Molecular Genetics, IGM-CNR, via Abbiategrasso 207, 27100 Pavia, Italy.
| | - Miroslava Kissova
- Institute of Molecular Genetics, IGM-CNR, via Abbiategrasso 207, 27100 Pavia, Italy.
| | - Laura Bavagnoli
- Institute of Molecular Genetics, IGM-CNR, via Abbiategrasso 207, 27100 Pavia, Italy.
| | - Giovanni Maga
- Institute of Molecular Genetics, IGM-CNR, via Abbiategrasso 207, 27100 Pavia, Italy.
| | - Emmanuele Crespan
- Institute of Molecular Genetics, IGM-CNR, via Abbiategrasso 207, 27100 Pavia, Italy.
| |
Collapse
|
28
|
Williams JS, Lujan SA, Kunkel TA. Processing ribonucleotides incorporated during eukaryotic DNA replication. Nat Rev Mol Cell Biol 2016; 17:350-63. [PMID: 27093943 PMCID: PMC5445644 DOI: 10.1038/nrm.2016.37] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The information encoded in DNA is influenced by the presence of non-canonical nucleotides, the most frequent of which are ribonucleotides. In this Review, we discuss recent discoveries about ribonucleotide incorporation into DNA during replication by the three major eukaryotic replicases, DNA polymerases α, δ and ε. The presence of ribonucleotides in DNA causes short deletion mutations and may result in the generation of single- and double-strand DNA breaks, leading to genome instability. We describe how these ribonucleotides are removed from DNA through ribonucleotide excision repair and by topoisomerase I. We discuss the biological consequences and the physiological roles of ribonucleotides in DNA, and consider how deficiencies in their removal from DNA may be important in the aetiology of disease.
Collapse
Affiliation(s)
- Jessica S. Williams
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, United States
| | - Scott A. Lujan
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, United States
| | - Thomas A. Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, United States
| |
Collapse
|
29
|
Cerritelli SM, Crouch RJ. The Balancing Act of Ribonucleotides in DNA. Trends Biochem Sci 2016; 41:434-445. [PMID: 26996833 DOI: 10.1016/j.tibs.2016.02.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/01/2016] [Accepted: 02/09/2016] [Indexed: 11/28/2022]
Abstract
The abundance of ribonucleotides in DNA remained undetected until recently because they are efficiently removed by the ribonucleotide excision repair (RER) pathway, a process similar to Okazaki fragment (OF) processing after incision by Ribonuclease H2 (RNase H2). All DNA polymerases incorporate ribonucleotides during DNA synthesis. How many, when, and why they are incorporated has been the focus of intense work during recent years by many labs. In this review, we discuss recent advances in ribonucleotide incorporation by eukaryotic DNA polymerases that suggest an evolutionarily conserved role for ribonucleotides in DNA. We also review the data that indicate that removal of ribonucleotides has an important role in maintaining genome stability.
Collapse
Affiliation(s)
- Susana M Cerritelli
- Section on Formation of RNA, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Robert J Crouch
- Section on Formation of RNA, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
30
|
Crespan E, Furrer A, Rösinger M, Bertoletti F, Mentegari E, Chiapparini G, Imhof R, Ziegler N, Sturla SJ, Hübscher U, van Loon B, Maga G. Impact of ribonucleotide incorporation by DNA polymerases β and λ on oxidative base excision repair. Nat Commun 2016; 7:10805. [PMID: 26917111 PMCID: PMC4773436 DOI: 10.1038/ncomms10805] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 01/22/2016] [Indexed: 12/17/2022] Open
Abstract
Oxidative stress is a very frequent source of DNA damage. Many cellular DNA polymerases (Pols) can incorporate ribonucleotides (rNMPs) during DNA synthesis. However, whether oxidative stress-triggered DNA repair synthesis contributes to genomic rNMPs incorporation is so far not fully understood. Human specialized Pols β and λ are the important enzymes involved in the oxidative stress tolerance, acting both in base excision repair and in translesion synthesis past the very frequent oxidative lesion 7,8-dihydro-8-oxoguanine (8-oxo-G). We found that Pol β, to a greater extent than Pol λ can incorporate rNMPs opposite normal bases or 8-oxo-G, and with a different fidelity. Further, the incorporation of rNMPs opposite 8-oxo-G delays repair by DNA glycosylases. Studies in Pol β- and λ-deficient cell extracts suggest that Pol β levels can greatly affect rNMP incorporation opposite oxidative DNA lesions. Oxidative stress is a common source of DNA damage and is repaired by the base excision repair machinery, including polymerase beta. Here the authors find that polymerase beta, and to a lesser extent lambda, can mistakenly incorporate ribonucleotides during synthesis.
Collapse
Affiliation(s)
- Emmanuele Crespan
- DNA Enzymology &Molecular Virology Unit, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Antonia Furrer
- Department of Molecular Mechanisms of Disease, University of Zürich, CH-8057 Zürich, Switzerland
| | - Marcel Rösinger
- Department of Molecular Mechanisms of Disease, University of Zürich, CH-8057 Zürich, Switzerland
| | - Federica Bertoletti
- DNA Enzymology &Molecular Virology Unit, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Elisa Mentegari
- DNA Enzymology &Molecular Virology Unit, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Giulia Chiapparini
- DNA Enzymology &Molecular Virology Unit, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| | - Ralph Imhof
- Department of Molecular Mechanisms of Disease, University of Zürich, CH-8057 Zürich, Switzerland
| | - Nathalie Ziegler
- Department of Health Sciences and Technology, ETH Zurich, CH-8092 Zürich, Switzerland
| | - Shana J Sturla
- Department of Health Sciences and Technology, ETH Zurich, CH-8092 Zürich, Switzerland
| | - Ulrich Hübscher
- Department of Molecular Mechanisms of Disease, University of Zürich, CH-8057 Zürich, Switzerland
| | - Barbara van Loon
- Department of Molecular Mechanisms of Disease, University of Zürich, CH-8057 Zürich, Switzerland
| | - Giovanni Maga
- DNA Enzymology &Molecular Virology Unit, Institute of Molecular Genetics IGM-CNR, via Abbiategrasso 207, I-27100 Pavia, Italy
| |
Collapse
|
31
|
Measuring the elasticity of ribonucleotide(s)-containing DNA molecules using AFM. Methods Mol Biol 2016; 1297:43-57. [PMID: 25895994 DOI: 10.1007/978-1-4939-2562-9_3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ribonucleotides, ribonucleoside monophosphates (rNMPs), have been revealed as possibly the most noncanonical nucleotides in genomic DNA. rNMPs, either not removed from Okazaki fragments during DNA replication or incorporated and scattered throughout the genome, pose a perturbation to the structure and a threat to the stability of DNA. The instability of DNA is mainly due to the extra 2'-hydroxyl (OH) group of rNMPs which give rise to local structural effects, which may disturb various molecular interactions in cells. As a result of these structural perturbations by rNMPs, the elastic properties of DNA are also affected. Here, we show the approach to test whether the presence of rNMPs in DNA duplexes could alter the elasticity of DNA by implementing atomic force microscopy (AFM)-based single molecule force-measurements of short rNMP(s)-containing oligonucleotides (oligos).
Collapse
|
32
|
Su Y, Egli M, Guengerich FP. Mechanism of Ribonucleotide Incorporation by Human DNA Polymerase η. J Biol Chem 2016; 291:3747-56. [PMID: 26740629 DOI: 10.1074/jbc.m115.706226] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Indexed: 12/12/2022] Open
Abstract
Ribonucleotides and 2'-deoxyribonucleotides are the basic units for RNA and DNA, respectively, and the only difference is the extra 2'-OH group on the ribonucleotide sugar. Cellular rNTP concentrations are much higher than those of dNTP. When copying DNA, DNA polymerases not only select the base of the incoming dNTP to form a Watson-Crick pair with the template base but also distinguish the sugar moiety. Some DNA polymerases use a steric gate residue to prevent rNTP incorporation by creating a clash with the 2'-OH group. Y-family human DNA polymerase η (hpol η) is of interest because of its spacious active site (especially in the major groove) and tolerance of DNA lesions. Here, we show that hpol η maintains base selectivity when incorporating rNTPs opposite undamaged DNA and the DNA lesions 7,8-dihydro-8-oxo-2'-deoxyguanosine and cyclobutane pyrimidine dimer but with rates that are 10(3)-fold lower than for inserting the corresponding dNTPs. X-ray crystal structures show that the hpol η scaffolds the incoming rNTP to pair with the template base (dG) or 7,8-dihydro-8-oxo-2'-deoxyguanosine with a significant propeller twist. As a result, the 2'-OH group avoids a clash with the steric gate, Phe-18, but the distance between primer end and Pα of the incoming rNTP increases by 1 Å, elevating the energy barrier and slowing polymerization compared with dNTP. In addition, Tyr-92 was identified as a second line of defense to maintain the position of Phe-18. This is the first crystal structure of a DNA polymerase with an incoming rNTP opposite a DNA lesion.
Collapse
Affiliation(s)
- Yan Su
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Martin Egli
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - F Peter Guengerich
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| |
Collapse
|
33
|
Cilli P, Minoprio A, Bossa C, Bignami M, Mazzei F. Formation and Repair of Mismatches Containing Ribonucleotides and Oxidized Bases at Repeated DNA Sequences. J Biol Chem 2015; 290:26259-69. [PMID: 26338705 PMCID: PMC4646274 DOI: 10.1074/jbc.m115.679209] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/02/2015] [Indexed: 11/06/2022] Open
Abstract
The cellular pool of ribonucleotide triphosphates (rNTPs) is higher than that of deoxyribonucleotide triphosphates. To ensure genome stability, DNA polymerases must discriminate against rNTPs and incorporated ribonucleotides must be removed by ribonucleotide excision repair (RER). We investigated DNA polymerase β (POL β) capacity to incorporate ribonucleotides into trinucleotide repeated DNA sequences and the efficiency of base excision repair (BER) and RER enzymes (OGG1, MUTYH, and RNase H2) when presented with an incorrect sugar and an oxidized base. POL β incorporated rAMP and rCMP opposite 7,8-dihydro-8-oxoguanine (8-oxodG) and extended both mispairs. In addition, POL β was able to insert and elongate an oxidized rGMP when paired with dA. We show that RNase H2 always preserves the capacity to remove a single ribonucleotide when paired to an oxidized base or to incise an oxidized ribonucleotide in a DNA duplex. In contrast, BER activity is affected by the presence of a ribonucleotide opposite an 8-oxodG. In particular, MUTYH activity on 8-oxodG:rA mispairs is fully inhibited, although its binding capacity is retained. This results in the reduction of RNase H2 incision capability of this substrate. Thus complex mispairs formed by an oxidized base and a ribonucleotide can compromise BER and RER in repeated sequences.
Collapse
Affiliation(s)
- Piera Cilli
- From the Department of Environment and Primary Prevention, Istituto Superiore di Sanità, 00161 Roma and the Department of Science, University Roma Tre, 00154 Roma, Italy
| | - Anna Minoprio
- From the Department of Environment and Primary Prevention, Istituto Superiore di Sanità, 00161 Roma and
| | - Cecilia Bossa
- From the Department of Environment and Primary Prevention, Istituto Superiore di Sanità, 00161 Roma and
| | - Margherita Bignami
- From the Department of Environment and Primary Prevention, Istituto Superiore di Sanità, 00161 Roma and
| | - Filomena Mazzei
- From the Department of Environment and Primary Prevention, Istituto Superiore di Sanità, 00161 Roma and
| |
Collapse
|
34
|
Ding J, Taylor MS, Jackson AP, Reijns MAM. Genome-wide mapping of embedded ribonucleotides and other noncanonical nucleotides using emRiboSeq and EndoSeq. Nat Protoc 2015; 10:1433-44. [PMID: 26313479 DOI: 10.1038/nprot.2015.099] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ribonucleotides are the most common noncanonical nucleotides incorporated into the genome of replicating cells. They are efficiently removed by ribonucleotide excision repair initiated by RNase H2 cleavage. In the absence of RNase H2, such embedded ribonucleotides can be used to track DNA polymerase activity in vivo. To determine their precise location in Saccharomyces cerevisiae, we developed embedded ribonucleotide sequencing (emRiboSeq), which uses recombinant RNase H2 to selectively create ligatable 3'-hydroxyl groups, in contrast to alternative methods that use alkaline hydrolysis. EmRiboSeq allows reproducible, strand-specific and potentially quantitative detection of embedded ribonucleotides at single-nucleotide resolution. For the genome-wide mapping of other noncanonical bases, RNase H2 can be replaced with specific nicking endonucleases in this protocol; we term this method endonuclease sequencing (EndoSeq). With the protocol taking <5 d to complete, these methods allow the in vivo study of DNA replication and repair, including the identification of replication origins and termination regions.
Collapse
Affiliation(s)
- James Ding
- Medical Research Council (MRC) Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| | - Martin S Taylor
- Medical Research Council (MRC) Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| | - Andrew P Jackson
- Medical Research Council (MRC) Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| | - Martin A M Reijns
- Medical Research Council (MRC) Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| |
Collapse
|
35
|
Creative template-dependent synthesis by human polymerase mu. Proc Natl Acad Sci U S A 2015; 112:E4530-6. [PMID: 26240373 DOI: 10.1073/pnas.1505798112] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Among the many proteins used to repair DNA double-strand breaks by nonhomologous end joining (NHEJ) are two related family X DNA polymerases, Pol λ and Pol µ. Which of these two polymerases is preferentially used for filling DNA gaps during NHEJ partly depends on sequence complementarity at the break, with Pol λ and Pol µ repairing complementary and noncomplementary ends, respectively. To better understand these substrate preferences, we present crystal structures of Pol µ on a 2-nt gapped DNA substrate, representing three steps of the catalytic cycle. In striking contrast to Pol λ, Pol µ "skips" the first available template nucleotide, instead using the template base at the 5' end of the gap to direct nucleotide binding and incorporation. This remarkable divergence from canonical 3'-end gap filling is consistent with data on end-joining substrate specificity in cells, and provides insights into polymerase substrate choices during NHEJ.
Collapse
|
36
|
Vaisman A, Woodgate R. Redundancy in ribonucleotide excision repair: Competition, compensation, and cooperation. DNA Repair (Amst) 2015; 29:74-82. [PMID: 25753809 DOI: 10.1016/j.dnarep.2015.02.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 02/07/2015] [Accepted: 02/09/2015] [Indexed: 10/24/2022]
Abstract
The survival of all living organisms is determined by their ability to reproduce, which in turn depends on accurate duplication of chromosomal DNA. In order to ensure the integrity of genome duplication, DNA polymerases are equipped with stringent mechanisms by which they select and insert correctly paired nucleotides with a deoxyribose sugar ring. However, this process is never 100% accurate. To fix occasional mistakes, cells have evolved highly sophisticated and often redundant mechanisms. A good example is mismatch repair (MMR), which corrects the majority of mispaired bases and which has been extensively studied for many years. On the contrary, pathways leading to the replacement of nucleotides with an incorrect sugar that is embedded in chromosomal DNA have only recently attracted significant attention. This review describes progress made during the last few years in understanding such pathways in both prokaryotes and eukaryotes. Genetic studies in Escherichia coli and Saccharomyces cerevisiae demonstrated that MMR has the capacity to replace errant ribonucleotides, but only when the base is mispaired. In contrast, the major evolutionarily conserved ribonucleotide repair pathway initiated by the ribonuclease activity of type 2 Rnase H has broad specificity. In yeast, this pathway also requires the concerted action of Fen1 and pol δ, while in bacteria it can be successfully completed by DNA polymerase I. Besides these main players, all organisms contain alternative enzymes able to accomplish the same tasks, although with differing efficiency and fidelity. Studies in bacteria have very recently demonstrated that isolated rNMPs can be removed from genomic DNA by error-free nucleotide excision repair (NER), while studies in yeast suggest the involvement of topoisomerase 1 in alternative mutagenic ribonucleotide processing. This review summarizes the most recent progress in understanding the ribonucleotide repair mechanisms in prokaryotes and eukaryotes.
Collapse
Affiliation(s)
- Alexandra Vaisman
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3371, USA
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3371, USA.
| |
Collapse
|
37
|
Structural basis for the binding and incorporation of nucleotide analogs with L-stereochemistry by human DNA polymerase λ. Proc Natl Acad Sci U S A 2014; 111:E3033-42. [PMID: 25015085 DOI: 10.1073/pnas.1401286111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although lamivudine and emtricitabine, two L-deoxycytidine analogs, have been widely used as antiviral drugs for years, a structural basis for D-stereoselectivity against L-dNTPs, enantiomers of natural nucleotides (D-dNTPs), by any DNA polymerase or reverse transcriptase has not been established due to lack of a ternary structure of a polymerase, DNA, and an incoming L-dNTP. Here, we report 2.10-2.25 Å ternary crystal structures of human DNA polymerase λ, DNA, and L-deoxycytidine 5'-triphosphate (L-dCTP), or the triphosphates of lamivudine ((-)3TC-TP) and emtricitabine ((-)FTC-TP) with four ternary complexes per asymmetric unit. The structures of these 12 ternary complexes reveal that relative to D-deoxycytidine 5'-triphosphate (D-dCTP) in the canonical ternary structure of Polλ-DNA-D-dCTP, L-dCTP, (-)3TC-TP, and (-)FTC-TP all have their ribose rotated by 180°. Among the four ternary complexes with a specific L-nucleotide, two are similar and show that the L-nucleotide forms three Watson-Crick hydrogen bonds with the templating nucleotide dG and adopts a chair-like triphosphate conformation. In the remaining two similar ternary complexes, the L-nucleotide surprisingly interacts with the side chain of a conserved active site residue R517 through one or two hydrogen bonds, whereas the templating dG is anchored by a hydrogen bond with the side chain of a semiconserved residue Y505. Furthermore, the triphosphate of the L-nucleotide adopts an unprecedented N-shaped conformation. Our mutagenic and kinetic studies further demonstrate that the side chain of R517 is critical for the formation of the abovementioned four complexes along proposed catalytic pathways for L-nucleotide incorporation and provide the structural basis for the D-stereoselectivity of a DNA polymerase.
Collapse
|
38
|
Abstract
While primordial life is thought to have been RNA-based (Cech, Cold Spring Harbor Perspect. Biol. 4 (2012) a006742), all living organisms store genetic information in DNA, which is chemically more stable. Distinctions between the RNA and DNA worlds and our views of "DNA" synthesis continue to evolve as new details emerge on the incorporation, repair and biological effects of ribonucleotides in DNA genomes of organisms from bacteria through humans.
Collapse
Affiliation(s)
- Jessica S Williams
- Laboratory of Molecular Genetics and Laboratory of Structural Biology, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, United States
| | - Thomas A Kunkel
- Laboratory of Molecular Genetics and Laboratory of Structural Biology, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC 27709, United States.
| |
Collapse
|
39
|
Bebenek K, Pedersen LC, Kunkel TA. Structure-function studies of DNA polymerase λ. Biochemistry 2014; 53:2781-92. [PMID: 24716527 PMCID: PMC4018081 DOI: 10.1021/bi4017236] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
![]()
DNA polymerase λ
(pol λ) functions in DNA repair with
its main roles considered to be filling short gaps during repair of
double-strand breaks by nonhomologous end joining and during base
excision repair. As indicated by structural and biochemical studies
over the past 10 years, pol λ shares many common properties
with other family X siblings (pol β, pol μ, and terminal
deoxynucleotidyl transferase) but also has unique structural features
that determine its specific functions. In this review, we consider
how structural studies over the past decade furthered our understanding
of the behavior and biological roles of pol λ.
Collapse
Affiliation(s)
- Katarzyna Bebenek
- Laboratory of Structural Biology and ‡Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health , Research Triangle Park, North Carolina 27709, United States
| | | | | |
Collapse
|
40
|
Structures of the Leishmania infantum polymerase beta. DNA Repair (Amst) 2014; 18:1-9. [PMID: 24666693 DOI: 10.1016/j.dnarep.2014.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/28/2014] [Accepted: 03/01/2014] [Indexed: 11/21/2022]
Abstract
Protozoans of the genus Leishmania, the pathogenic agent causing leishmaniasis, encode the family X DNA polymerase Li Pol β. Here, we report the first crystal structures of Li Pol β. Our pre- and post-catalytic structures show that the polymerase adopts the common family X DNA polymerase fold. However, in contrast to other family X DNA polymerases, the dNTP-induced conformational changes in Li Pol β are much more subtle. Moreover, pre- and post-catalytic structures reveal that Li Pol β interacts with the template strand through a nonconserved, variable region known as loop3. Li Pol β Δloop3 mutants display a higher catalytic rate, catalytic efficiency and overall error rates with respect to WT Li Pol β. These results further demonstrate the subtle structural variability that exists within this family of enzymes and provides insight into how this variability underlies the substantial functional differences among their members.
Collapse
|
41
|
Moon AF, Pryor JM, Ramsden DA, Kunkel TA, Bebenek K, Pedersen LC. Sustained active site rigidity during synthesis by human DNA polymerase μ. Nat Struct Mol Biol 2014; 21:253-60. [PMID: 24487959 PMCID: PMC4164209 DOI: 10.1038/nsmb.2766] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 12/26/2013] [Indexed: 01/09/2023]
Abstract
DNA polymerase μ (Pol μ) is the only template-dependent human DNA polymerase capable of repairing double-strand DNA breaks (DSBs) with unpaired 3' ends in nonhomologous end joining (NHEJ). To probe this function, we structurally characterized Pol μ's catalytic cycle for single-nucleotide incorporation. These structures indicate that, unlike other template-dependent DNA polymerases, Pol μ shows no large-scale conformational changes in protein subdomains, amino acid side chains or DNA upon dNTP binding or catalysis. Instead, the only major conformational change is seen earlier in the catalytic cycle, when the flexible loop 1 region repositions upon DNA binding. Pol μ variants with changes in loop 1 have altered catalytic properties and are partially defective in NHEJ. The results indicate that specific loop 1 residues contribute to Pol μ's unique ability to catalyze template-dependent NHEJ of DSBs with unpaired 3' ends.
Collapse
Affiliation(s)
- Andrea F Moon
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - John M Pryor
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Dale A Ramsden
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Thomas A Kunkel
- 1] Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA. [2] Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Katarzyna Bebenek
- 1] Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA. [2] Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Lars C Pedersen
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| |
Collapse
|
42
|
Affiliation(s)
- Keith W Caldecott
- Genome Damage and Stability Centre, University of Sussex, Falmer, UK
| |
Collapse
|