Abstract— The relative biological importance of cis‐syn cyclobutane dimer and pyrimidine(6–4)pyr‐imidone photoadduct ([6–4] photoadduct) appears to be dependent on the species, dipyrimidine sites local conformational variation induced at damaged sites. single‐stranded deoxyn‐ucleotide 10‐mers containing site‐specific (6–4) adduct or thymidylyl (3'‐5')‐thymidine were generated by direct photolysis d(CGCATTACGC) with UVC (220–260 nm) irradiation UVB (260–320 photosensitization....

Abstract Bacterial small RNAs (sRNAs) are known regulators in many physiological processes. In Escherichia coli, a large number of sRNAs have been predicted, among which only about hundred experimentally validated. Despite considerable research, the majority their functions remain uncovered. Therefore, collective analysis roles specific cellular processes may provide an effective approach to identify functions. Here, we constructed collection plasmids overexpressing 99 individual and...

The multifunctional DNAzyme (Dz) delivery system is developed based on nano-sized graphene oxide (nGO) for simultaneous detection and knockdown of the target gene. Dz/nGO complex allowed convenient monitoring HCV mRNA in living cells silencing gene expression by Dz-mediated catalytic cleavage concurrently.

hHR23B is the human homologue of yeast protein RAD23 and known to participate in DNA repair by stabilizing xeroderma pigmentosum group C protein. However, also have many important functions related general proteolysis. consists N-terminal ubiquitin-like (UbL), ubiquitin association 1 (UBA1), binding, UBA2 domains. The UBA domains interact with (Ub) inhibit assembly polyubiquitin. On other hand, UbL domain interacts poly-Ub binding site 2 (PUbS2) S5a protein, which can carry polyubiquitinated...

A GO-to solution: simple graphene oxide (GO)-based assay to screen for selective inhibitors of a hepatitis C virus (HCV) helicase along with severe acute respiratory syndrome coronavirus (SARS CoV) was tested (see scheme). single found five highly the HCV orthologous SARS CoV helicase. Some these hits were validated using same GO-based assay. Worldwide, over 170 million people have infections.1 Chronic infection leads liver diseases such as cirrhosis and hepatocarcinoma is major reason...

The influenza A virus, a severe pandemic pathogen, has segmented RNA genome consisting of eight single-stranded molecules. 5' and 3' ends each segment recognized by the virus RNA-dependent polymerase direct both transcription replication virus's genome. Promoter binding viral formation an active open complex are prerequisites for proliferation. Here we describe solution structure this promoter as solved multidimensional, heteronuclear magnetic resonance spectroscopy. Our studies show that...

The human RNA editing enzyme ADAR1 (double-stranded deaminase I) deaminates adenine in pre-mRNA to yield inosine, which codes as guanine. has two left-handed Z-DNA binding domains, Zα and Zβ, at its NH2-terminus preferentially binds Z-DNA, rather than B-DNA, with high affinity. cocrystal structure of ZαADAR1 complexed showed that one monomeric domain strand double-stranded DNA a second monomer the opposite 2-fold symmetry respect helical axis. It remains unclear how protein specifically...

A strategy to diversely functionalize the C7-position of DMXAA has been developed as a means discover potential human-STING agonists.

Retinoic acid-inducible gene I (RIG-I) recognizes specific molecular patterns of viral RNAs for inducing type interferon. The C-terminal domain (CTD) RIG-I binds to double-stranded RNA (dsRNA) with the 5′-triphosphate (5′-PPP), which induces a conformational change in an active form. It has been suggested that detects infection influenza A virus by recognizing 5′-triphosphorylated panhandle structure genome. Influenza unique sharp helical bending. In spite extensive studies how activate...

The pyrimidine(6–4)pyrimidone photoproduct [(6–4) adduct] is one of the major photoproducts induced by UV irradiation DNA and occurs at TpT sites. (6–4) adduct highly mutagenic leads most often to a 3′ T → C transition with 85% replicating error frequency [LeClerc, J. E., Borden, A. & Lawrence, C. W. (1991) Proc. Natl. Acad. Sci. USA 88, 9685–9689]. To determine origin specific adduct, we have used experimental NMR restraints molecular dynamics solution structure (6–4)-lesion decamer...

Although it is commonly known as a helix breaker, proline residues have been found in the alpha-helical regions of many peptides and proteins. The antimicrobial peptide gaegurin displays structure has central residue (P14). activity its alanine derivative (P14A) were determined by various spectroscopic methods, restrained molecular dynamics, biological assays. Both P14 P14A exhibited cooperative formation solution, but helical stability was reduced substantially when compared to that P14A....

The helicase and RNaseD C-terminal (HRDC) domain, conserved among members of the RecQ family, regulates activity by virtue variations in its surface residues. HRDC domain Bloom syndrome protein (BLM) is known as a critical determinant dissolution function double Holliday junctions BLM–Topoisomerase IIIα complex. In this study, we determined solution structure human BLM characterized DNA-binding activity. consists five α-helices with hydrophobic 3 10 -helical loop between helices 1 2 an...

Z-DNA is produced in a long genomic DNA by binding proteins, through formation of two B-Z junctions with the extrusion one base pair from each junction. To answer question how proteins induce transitions CG-rich segments while maintaining B-conformation surrounding segments, we investigated kinetics and thermodynamics base-pair openings 13-bp complex protein, Zα(ADAR1). We also studied perturbations backbone Zα(ADAR1) upon to DNA. Our study demonstrates initial contact conformation as an...

The structure of an active analog the antibacterial peptide gaegurin was investigated by CD and NMR spectroscopy. NOE connectivities showed that 21 out 24 residues formed α‐helix despite presence a central proline. analysis indicates helix is in fast equilibrium with random coil. From chemical shift amide protons, distances hydrogen bonding were calculated, manifested obvious periodicity which implied kink middle helix. 1D proton exchange experiments provided further evidence exceptionally...

XPF and ERCC1 exist as a heterodimer to be stable active in cells catalyze DNA cleavage on the 5'-side of lesion during nucleotide excision repair. To characterize specific interaction between ERCC1, we expressed human binding domain (XPF-EB) (ERCC1-FB) Escherichia coli. Milligram quantities were characterized with gel filtration chromatography, an Ni(2+)-NTA assay, analytical ultracentrifugation. Cross-linking experiments at high salt concentrations revealed that interacts mainly through...

Abstract Probably the most unusual class of proteins in nature is intrinsically unstructured (IUPs), because they are not structured yet play essential roles protein‐protein signaling. Many IUPs can bind different proteins, and many cases, adopt bound conformations. The p21 protein a small IUP (164 residues) that ubiquitous cellular signaling, for example, cell cycle control, apoptosis, transcription, differentiation, so forth; it binds to approximately 25 targets. How does this small,...

Z-DNA binding proteins (ZBPs) play important roles in RNA editing, innate immune response and viral infection. Structural biophysical studies show that ZBPs initially form an intermediate complex with B-DNA for B–Z conversion. However, a comprehensive understanding of the mechanism transition is still lacking, due to absence structural information on complex. Here, we report solution structure Zα domain ZBP-containing protein kinase from Carassius auratus (caZαPKZ). We quantitatively...

Human RNA editing enzyme ADAR1 deaminates adenosine in pre-mRNA to yield inosine. The Zα domain of human (hZαADAR1) binds specifically left-handed Z-RNA as well Z-DNA and stabilizes the Z-conformation. To answer question how hZαADAR1 can induce both B–Z transition DNA A–Z RNA, we investigated structure dynamics complex with 6-base-pair or Z-RNA. We performed chemical shift perturbation relaxation dispersion experiments on upon binding Our study demonstrates unique during which protein forms...

Abstract The Arabidopsis HY5 protein is a basic leucine zipper (bZIP) transcription factor that promotes photomorphogenesis. binds directly to the promoters of light responsible element containing G‐box and thus regulates their transcriptional activity. level activity are negatively regulated, in light‐dependent manner, by interaction with COP1 protein, which targets for proteasome‐mediated degradation nucleus. Despite its essential roles plant development, no structural information exists...