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El-Kamand S, Du Plessis MD, Lawson T, Cubeddu L, Gamsjaeger R. Expression, Purification, and Solution-State NMR Analysis of the Two Human Single-Stranded DNA-Binding Proteins hSSB1 (NABP2/OBFC2B) and hSSB2 (NAPB1/OBFC2A). Methods Mol Biol 2021; 2281:229-240. [PMID: 33847962 DOI: 10.1007/978-1-0716-1290-3_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Single-stranded DNA-binding proteins (SSBs) are essential to all living organisms as protectors and guardians of the genome. Apart from the well-characterized RPA, humans have also evolved two further SSBs, termed hSSB1 and hSSB2. Over the last few years, we have used NMR spectroscopy to determine the molecular and structural details of both hSSBs and their interactions with DNA and RNA. Here we provide a detailed overview of how to express and purify recombinant versions of these important human proteins for the purpose of detailed structural analysis by high-resolution solution-state NMR.
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Affiliation(s)
- Serene El-Kamand
- School of Science, Western Sydney University, Penrith, NSW, Australia
| | | | - Teegan Lawson
- School of Science, Western Sydney University, Penrith, NSW, Australia
| | - Liza Cubeddu
- School of Science, Western Sydney University, Penrith, NSW, Australia.
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia.
| | - Roland Gamsjaeger
- School of Science, Western Sydney University, Penrith, NSW, Australia.
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia.
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Lawson T, El-Kamand S, Boucher D, Duong DC, Kariawasam R, Bonvin AMJJ, Richard DJ, Gamsjaeger R, Cubeddu L. The structural details of the interaction of single-stranded DNA binding protein hSSB2 (NABP1/OBFC2A) with UV-damaged DNA. Proteins 2019; 88:319-326. [PMID: 31443132 DOI: 10.1002/prot.25806] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/02/2019] [Accepted: 08/19/2019] [Indexed: 12/17/2022]
Abstract
Single-stranded DNA-binding proteins (SSBs) are required for all known DNA metabolic events such as DNA replication, recombination and repair. While a wealth of structural and functional data is available on the essential human SSB, hSSB1 (NABP2/OBFC2B), the close homolog hSSB2 (NABP1/OBFC2A) remains relatively uncharacterized. Both SSBs possess a well-structured OB (oligonucleotide/oligosaccharide-binding) domain that is able to recognize single-stranded DNA (ssDNA) followed by a flexible carboxyl-tail implicated in the interaction with other proteins. Despite the high sequence similarity of the OB domain, several recent studies have revealed distinct functional differences between hSSB1 and hSSB2. In this study, we show that hSSB2 is able to recognize cyclobutane pyrimidine dimers (CPD) that form in cellular DNA as a consequence of UV damage. Using a combination of biolayer interferometry and NMR, we determine the molecular details of the binding of the OB domain of hSSB2 to CPD-containing ssDNA, confirming the role of four key aromatic residues in hSSB2 (W59, Y78, W82, and Y89) that are also conserved in hSSB1. Our structural data thus demonstrate that ssDNA recognition by the OB fold of hSSB2 is highly similar to hSSB1, indicating that one SSB may be able to replace the other in any initial ssDNA binding event. However, any subsequent recruitment of other repair proteins most likely depends on the divergent carboxyl-tail and as such is likely to be different between hSSB1 and hSSB2.
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Affiliation(s)
- Teegan Lawson
- School of Science and Health, Western Sydney University, Penrith, New South Wales, Australia
| | - Serene El-Kamand
- School of Science and Health, Western Sydney University, Penrith, New South Wales, Australia
| | - Didier Boucher
- Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Woolloongabba, Queensland, Australia
| | - Duc Cong Duong
- School of Science and Health, Western Sydney University, Penrith, New South Wales, Australia
| | - Ruvini Kariawasam
- School of Science and Health, Western Sydney University, Penrith, New South Wales, Australia
| | - Alexandre M J J Bonvin
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Derek J Richard
- Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Woolloongabba, Queensland, Australia
| | - Roland Gamsjaeger
- School of Science and Health, Western Sydney University, Penrith, New South Wales, Australia.,School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Liza Cubeddu
- School of Science and Health, Western Sydney University, Penrith, New South Wales, Australia.,School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
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Lawson T, El-Kamand S, Kariawasam R, Richard DJ, Cubeddu L, Gamsjaeger R. A Structural Perspective on the Regulation of Human Single-Stranded DNA Binding Protein 1 (hSSB1, OBFC2B) Function in DNA Repair. Comput Struct Biotechnol J 2019; 17:441-446. [PMID: 30996823 PMCID: PMC6451162 DOI: 10.1016/j.csbj.2019.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/25/2019] [Accepted: 03/26/2019] [Indexed: 12/11/2022] Open
Abstract
Single-stranded DNA binding (SSB) proteins are essential to protect singe-stranded DNA (ssDNA) that exists as a result of several important DNA repair pathways in living cells. In humans, besides the well-characterised Replication Protein A (RPA) we have described another SSB termed human SSB1 (hSSB1, OBFC2B) and have shown that this protein is an important player in the maintenance of the genome. In this review we define the structural and biophysical details of how hSSB1 interacts with both DNA and other essential proteins. While the presence of the oligonucleotide/oligosaccharide (OB) domain ensures ssDNA binding by hSSB1, it has also been shown to self-oligomerise as well as interact with and being modified by several proteins highlighting the versatility that hSSB1 displays in the context of DNA repair. A detailed structural understanding of these processes will likely lead to the designs of tailored hSSB1 inhibitors as anti-cancer drugs in the near future.
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Affiliation(s)
- Teegan Lawson
- School of Science and Health, Western Sydney University, Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Serene El-Kamand
- School of Science and Health, Western Sydney University, Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Ruvini Kariawasam
- School of Science and Health, Western Sydney University, Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Derek J Richard
- Genome Stability Laboratory, Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Woolloongabba, Queensland 4102, Australia
| | - Liza Cubeddu
- School of Science and Health, Western Sydney University, Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia.,School of Life and Environmental Sciences, University of Sydney, NSW 2006, Australia
| | - Roland Gamsjaeger
- School of Science and Health, Western Sydney University, Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia.,School of Life and Environmental Sciences, University of Sydney, NSW 2006, Australia
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