A5056971800- DNA and Nucleic Acid Chemistry
- RNA and protein synthesis mechanisms
- Advanced biosensing and bioanalysis techniques
- RNA Interference and Gene Delivery
- Enzyme Structure and Function
- Plant Genetic and Mutation Studies
- DNA Repair Mechanisms
- Metal-Organic Frameworks: Synthesis and Applications
- Luminescence and Fluorescent Materials
- Protein Structure and Dynamics
- Lanthanide and Transition Metal Complexes
Northwest A&F University
2018-2023
Pif1 is an SF1B helicase that evolutionarily conserved from bacteria to humans and plays multiple roles in maintaining genome stability both nucleus mitochondria. Though highly conserved, family harbors a large mechanistic diversity. Here, we report crystal structures of Thermus oshimai (ToPif1) alone complexed with partial duplex or single-stranded DNA. In the apo state complex DNA, ToPif1 monomeric its domain 2B/loop3 adopting closed open conformation, respectively. When forms stable dimer...
RecQ family helicases are highly conserved from bacteria to humans and have essential roles in maintaining genome stability. Mutations three human cause severe diseases with the main features of premature aging cancer predisposition. Most shared a domain arrangement which comprises helicase core, an C-terminal domain, auxiliary element RNaseD (HRDC) functions poorly understood. In this study, we systematically characterized HRDC E. coli various DNA transactions by single-molecule FRET. We...
Endogenous Bos taurus RECQL is predominantly monomeric
Chen et al. solved the crystal structure of bovine DHX36 bound to a DNA with G-quadruplex (G4) and single-stranded segment. They believed that mechanism they proposed may represent general model for describing how G4-unfolding helicase recognizes unfolds G4 DNA. Their conclusion is interesting, however, we noticed their linear substrate (DNAMyc) harbors Myc-promoter-derived G4-forming sequence was directly used without pre-folding. This raises question whether obtained really reflects...
Our data challenge Chen et al.'s interpretation of smFRET results, i.e. the repetitive unfolding G4 with one-base translocations. We believe that observed oscillatory curve represents alternate binding DHX36 to 3' and 5'G-tetrad G4s, rather than between canonical transformed non-canonical G4s. Noteworthily, our results reported here also call into question previously published helicase-mediated unfolding. Therefore,discriminating signal from is very important avoid misinterpreting results.
ABSTRACT G-quadruplexes (G4s) are unusual DNA structures and can stall replication, causing genomic instability for the cell. Although solved crystal structure of DHX36 helicase demonstrated that G4 was specifically targeted by a DHX36-specific motif (DSM), lack complete structural details general G4-resolving helicases without specific target motifs remains barrier to understanding molecular basis underlying recognition unfolding G4s. Herein, we present first X-ray Thermus oshimai Pif1 ( To...