A5049179272- DNA Repair Mechanisms
- DNA and Nucleic Acid Chemistry
- Bacterial Genetics and Biotechnology
- Epigenetics and DNA Methylation
- CRISPR and Genetic Engineering
- RNA and protein synthesis mechanisms
- Advanced biosensing and bioanalysis techniques
- Bacteriophages and microbial interactions
- Genetic Neurodegenerative Diseases
- Pneumonia and Respiratory Infections
- Microbial Metabolic Engineering and Bioproduction
- Streptococcal Infections and Treatments
- Peptidase Inhibition and Analysis
- Bacterial Infections and Vaccines
- PARP inhibition in cancer therapy
- Biopolymer Synthesis and Applications
- 14-3-3 protein interactions
- Enzyme Catalysis and Immobilization
- Analytical Chemistry and Chromatography
- Cancer therapeutics and mechanisms
- Cancer Genomics and Diagnostics
- Ubiquitin and proteasome pathways
- Vibrio bacteria research studies
- Fungal and yeast genetics research
- Drug Transport and Resistance Mechanisms
University of Bristol
2018-2024
University of Sheffield
2012-2023
Telio (Norway)
2018
Elisa (Finland)
2018
University of Sussex
2014-2015
University of Manchester
2013
University of Michigan
2012
Barcelona Biomedical Research Park
2011
53BP1 plays multiple roles in mammalian DNA damage repair, mediating pathway choice and facilitating double-strand break repair heterochromatin. Although it possesses a C-terminal BRCT2 domain, commonly involved phospho-peptide binding other proteins, initial recruitment of to sites depends on interaction with histone post-translational modifications—H4K20me2 H2AK13/K15ub—downstream the early γH2AX phosphorylation mark damage. We now show that, contrary current models, 53BP1-BRCT2 domain...
Significance Single-stranded DNA (ssDNA) is a key intermediate in many cellular transactions, including replication, repair, and recombination. Nascent ssDNA rapidly bound by the Replication Protein A (RPA) complex, forming nucleoprotein filament that both stabilizes mediates downstream processing events. Paradoxically, however, very high affinity of RPA for may block recruitment further factors. In this work, we show RPA–ssDNA filaments are specifically targeted human HELB helicase....
Ring-like structural maintenance of chromosome (SMC) complexes are crucial for genome organization and operate through mechanisms DNA entrapment loop extrusion. Here, we explore the loading process bacterial SMC complex MukBEF. Using cryoelectron microscopy (cryo-EM), demonstrate that ATP binding opens one MukBEF's three potential entry gates, exposing a capture site positions at open neck gate. We discover gp5.9 protein bacteriophage T7 blocks this by mimicry, thereby preventing...
Following infection of bacterial cells, bacteriophage modulate double-stranded DNA break repair pathways to protect themselves from host immunity systems and prioritise their own recombinases. Here, we present biochemical structural analysis two phage proteins, gp5.9 Abc2, which target the resection complex RecBCD. These exemplify contrasting mechanisms for control in RecBCD is either inhibited or co-opted benefit invading phage. Gp5.9 completely inhibits by preventing it binding DNA. The...
CtIP is involved in the resection of broken DNA during S and G2 phases cell cycle for repair by recombination. Acting with MRN complex, it plays a particularly important role handling complex end structures localised nucleolytic processing termini preparation longer range resection. Here we show that human tetrameric protein adopting dumbbell architecture which binding domains are connected long coiled-coils. The binds two short duplexes high affinity bridges molecules trans. potentiated...
The consumption of red meat is a risk factor in human colorectal cancer (CRC). One hypothesis that facilitates the nitrosation bile acid conjugates and amino acids, which rapidly convert to DNA-damaging carcinogens. Indeed, toxic mutagenic DNA adduct O(6)-carboxymethylguanine (O(6)-CMG) frequently present DNA, increases abundance people with high levels dietary may therefore be causative CRC. Previous reports suggested O(6)-CMG not substrate for version damage reversal protein...
Alkyltransferase-like (ATL) proteins in Schizosaccharomyces pombe (Atl1) and Thermus thermophilus (TTHA1564) protect against the adverse effects of DNA alkylation damage by flagging O 6 -alkylguanine lesions for nucleotide excision repair (NER). We show that both ATL bind with high affinity to oligodeoxyribonucleotides containing -alkylguanines differing size, polarity, charge alkyl group. However, Atl1 shows a greater ability than TTHA1564 distinguish between guanine an unprecedented...
Streptococcus pneumoniae is a major human pathogen that can cause severe invasive diseases such as pneumonia, septicaemia and meningitis. Young children are at particularly high risk, with an estimated 3-4 million cases of disease between 300 000 500 deaths attributable to pneumococcal each year. The haemolytic toxin pneumolysin (Ply) primary virulence factor for this bacterium, yet despite its key role in pathogenesis, immune evasion transmission, the regulation Ply production not well...
Human exposure to DNA alkylating agents is poorly characterized, partly because only a limited range of specific alkyl adducts have been quantified. The human repair protein, O6-methylguanine O6-methyltransferase (MGMT), irreversibly transfers the group from O6-alkylguanines (O6-alkGs) an acceptor cysteine, allowing simultaneous detection multiple O6-alkG modifications in by mass spectrometric analysis MGMT active site peptide (ASP). Recombinant was incubated with oligodeoxyribonucleotides...
N-nitrosation of glycine and its derivatives generates potent alkylating agents that can lead to the formation O 6 -carboxymethylguanine (O -CMG) in DNA.O -CMG has been identified DNA derived from human colon tissue, occurrence linked diets high red processed meats.By analogy -methylguanine, is expected be highly mutagenic, inducing G A mutations during replication increase risk gastrointestinal other cancers.Two crystal structures dodecamers d(CGCG[O -CMG]ATTCGCG) d(CGC[O -CMG]A ATTCGCG)...
Cancer cells display high levels of DNA damage and replication stress, vulnerabilities that could be exploited by drugs targeting repair proteins. Human CtIP promotes homology-mediated double-strand breaks (DSBs) protects stalled forks from nucleolytic degradation, thus representing an attractive candidate for targeted cancer therapy. Here, we establish a peptide mimetic the tetramerization motif inhibits activity. The hydrocarbon-stapled encompassing amino acid residues 18 to 28 (SP18-28)...
Toxin-antitoxin (TA) systems are present in many bacteria and play important roles bacterial growth, physiology, pathogenicity. Those that best studied the type II TA systems, which both toxins antitoxins proteins. The HicAB system is one of prototypic found species. Complex interactions between protein toxin (HicA), antitoxin (HicB), DNA upstream encoding genes regulate activity this system, but few structural details available about how HicA destabilizes HicB-DNA complex. Here, we...
SUMO is a small post-translational modifier, that attached to lysine residues in target proteins. It acts by altering protein-protein interactions, protein localisation and activity. chains can also act as substrates for ubiquitination, resulting proteasome-mediated degradation of the protein. removed from proteins one number specific proteases. The processes sumoylation desumoylation have well documented roles DNA metabolism maintenance chromatin structure. To further analyse role this...
DNA2 is an essential enzyme involved in DNA replication and repair eukaryotes. In a search for homologues of this protein, we identified characterised Geobacillus stearothermophilus Bad, bacterial helicase-nuclease with similarity to human DNA2. We show that Bad contains Fe-S cluster identify four cysteine residues are likely co-ordinate the by analogy The purified specifically recognises ss-dsDNA junctions possesses ssDNA-dependent ATPase, ssDNA binding, endonuclease, 5' 3' translocase...
We show that DNA containing a conformationally-locked anti analogue of O6-alkylguanine is poor substrate for human O6-methylguanine–DNA methyltransferase (MGMT) and the alkyltransferase-like protein, Atl1. This highlights requirement syn conformation rationalises why certain O6-alkylguanines are MGMT substrates.
Abstract The human DNA repair factor CtIP helps to initiate the resection of double-stranded breaks for by homologous recombination, in part through its ability bind and bridge molecules. However, is a natively disordered protein that bears no apparent similarity other DNA-binding proteins so structural basis these activities remains unclear. In this work, we have used bulk binding, single molecule tracking, bridging assays study wild-type variant better define binding domains effects...
Ring-like structural maintenance of chromosomes (SMC) complexes are crucial for genome organization and operate through mechanisms DNA entrapment loop extrusion. Here, we explore the loading process bacterial SMC complex MukBEF. Using electron cryomicroscopy (cryo-EM), demonstrate that ATP binding opens one MukBEF's three potential entry gates, exposing a capture site positions at open neck gate. We discover gp5.9 protein bacteriophage T7 blocks this by mimicry, thereby preventing...
N-Nitrosation of glycine and its derivatives generates potent alkylating agents that can lead to the formation O(6)-carboxymethylguanine (O(6)-CMG) in DNA. O(6)-CMG has been identified DNA derived from human colon tissue occurrence linked diets high red processed meats, implying an association with induction colorectal cancer. By analogy O(6)-methylguanine, is expected be mutagenic, inducing G-to-A mutations may molecular basis increased cancer risk. Previously, crystal structure dodecamer...
Promutagenic O6-alkylguanine adducts in DNA are repaired humans by O6-methylguanine-DNA-methyltransferase (MGMT) an irreversible reaction. Here we describe the synthesis of a phosphoramidite that allows preparation oligodeoxyribonucleotides (ODNs) containing novel tricyclic thio analogue O6-methylguanine which third ring bridges 6-thio group and C7 7-deazapurine. These ODNs very poor substrates for MGMT poorly recognised alkyltransferase-like protein, Atl1. Examination active sites both Atl1...
Abstract Streptococcus pneumoniae is a major human pathogen that can cause severe invasive diseases such as pneumonia, septicaemia and meningitis. Young children are at particularly high risk, with an estimated half million deaths worldwide in those under five attributable to pneumococcal disease each year. The cytolytic toxin pneumolysin (Ply) primary virulence factor for this bacterium, yet despite its key role pathogenesis, immune evasion, transmission, the regulation of Ply production...
Abstract Following infection of bacterial cells, bacteriophage modulate double-stranded DNA break repair pathways to protect themselves from host immunity systems and prioritise their own recombinases. Here we present biochemical structural analysis two phage proteins, gp5.9 Abc2, which target the resection complex RecBCD. These exemplify contrasting mechanisms for control in RecBCD is either inhibited or co-opted benefit invading phage. Gp5.9 completely inhibits by preventing it binding...
Human HELB is a poorly-characterised helicase suggested to play both positive and negative regulatory roles in DNA replication recombination. In this work, we used bulk single molecule approaches characterise the biochemical activities of protein with particular focus on its interactions RPA RPA-ssDNA filaments. monomeric which binds tightly ssDNA site size ~20 nucleotides. It couples ATP hydrolysis translocation along 5′-to-3′ direction accompanied by formation loops an efficiency 1 per...