Structures of African swine fever virus topoisomerase complex and their implications.

African swine fever virus (ASFV) is the causal agent of African swine fever (ASF), which is contagious and highly lethal to domestic pigs and wild boars. The genome of ASFV encodes many proteins important for ASFV life cycle. The functional importance of topoisomerase AsfvTopII has been confirmed by in vivo and in vitro assays, but the structure of AsfvTopII is poorly studied.

Structural and functional insights into the helicase protein E5 of Mpox virus.

Mpox virus (MPXV) can cause mpox in humans. Due to its quick and wide spread in the past two years, mpox has turned into a significant public health concern. Helicase E5 is a multi-domain protein; its primer synthesis and DNA unwinding activity are required for genome uncoating and DNA replication of MPXV.

An Enhanced Vacuum-Assisted Resin Transfer Molding Process and Its Pressure Effect on Resin Infusion Behavior and Composite Material Performance.

In this paper, an enhanced VARTM process is proposed and its pressure effect on resin infusion behavior and composite material performance is studied to reveal the control mechanism of the fiber volume fraction and void content. The molding is vacuumized during the resin injection stage while it is pressurized during the mold filling and curing stages via a VARTM pressure control system designed in this paper. Theoretical calculations and simulation methods are used to reveal the resin's in-plane, transverse, and three-dimensional flow patterns in multi-layer media.

High-resolution crystal structure of RNA kinase ArK1 from G. acetivorans.

U47 phosphorylation (U47) is a novel tRNA modification discovered recently; it can confer thermal stability and nuclease resistance to tRNAs. U47 phosphorylation is catalyzed by Archaeal RNA kinase (Ark1) in an ATP-dependent manner. However, the structural basis for tRNA and/or ATP binding by Ark1 is unclear.

Structures and implications of the C962R protein of African swine fever virus.

African swine fever virus (ASFV) is highly contagious and can cause lethal disease in pigs. Although it has been extensively studied in the past, no vaccine or other useful treatment against ASFV is available. The genome of ASFV encodes more than 170 proteins, but the structures and functions for the majority of the proteins remain elusive, which hindered our understanding on the life cycle of ASFV and the development of ASFV-specific inhibitors.

Structural and functional studies of PCNA from African swine fever virus.

Proliferating cell nuclear antigen (PCNA) belongs to the DNA sliding clamp family. Via interacting with various partner proteins, PCNA plays critical roles in DNA replication, DNA repair, chromatin assembly, epigenetic inheritance, chromatin remodeling, and many other fundamental biological processes. Although PCNA and PCNA-interacting partner networks are conserved across species, PCNA of a given species is rarely functional in heterologous systems, emphasizing the importance of more representative PCNA studies.

Crystal structures and identification of novel Cd2+-specific DNA aptamer.

Cadmium (Cd) is one of the most toxic heavy metals. Exposure to Cd can impair the functions of the kidney, respiratory system, reproductive system and skeletal system. Cd2+-binding aptamers have been extensively utilized in the development of Cd2+-detecting devices; however, the underlying mechanisms remain elusive.

Structures and implications of the nuclease domain of human parvovirus B19 NS1 protein.

Infection of human parvovirus B19 (B19V) can cause a variety of diseases, such as hydrops fetalis, erythema infectiosum in children and acute arthropathy in women. Although B19V infection mainly occurs during childhood, about 50 % of adults are still susceptible to B19V infection. As the major replication protein of B19V, deletion of NS1 completely abolishes the infectivity of the virus.

Fluorescent Aptaswitch for Detection of Lead Ions.

Detection of metal ions has essential roles in biology, food industry, and environmental sciences. In this work, we developed a Pb detection strategy based on a fluorophore-tagged Pb-binding aptamer. The DNA aptamer changes its conformation on binding Pb, switching from an "off" state (low fluorescence) to an "on" state (high fluorescence).

Crystal structures and insights into precursor tRNA 5'-end processing by prokaryotic minimal protein-only RNase P.

Besides the canonical RNA-based RNase P, pre-tRNA 5'-end processing can also be catalyzed by protein-only RNase P (PRORP). To date, various PRORPs have been discovered, but the basis underlying substrate binding and cleavage by HARPs (homolog of Aquifex RNase P) remains elusive. Here, we report structural and biochemical studies of HARPs.

Crystallization and Structural Determination of 8-17 DNAzyme.

DNAzymes are a group of DNA molecules that can catalyze various chemical reactions. Owing to their great application potentials, DNAzymes have received significant attention. However, due to their intrinsic difficulties in crystallization and structural determination, only very limited structural information of DNAzymes is available to date.

Structure-guided development of Pb-binding DNA aptamers.

Owing to its great threat to human health and environment, Pb pollution has been recognized as a major public problem by the World Health Organization (WHO). Many DNA aptamers have been utilized in the development of Pb-detection sensors, but the underlying mechanisms remain elusive. Here, we report three Pb-complexed structures of the thrombin binding aptamer (TBA).

Improved support vector machine algorithm based on the influence of Gestational Diabetes Mellitus on the outcome of perinatal outcome by ultrasound imaging.

Objectives: In order to understand the incidence and epidemiological characteristics of gestational diabetes mellitus, the ultrasound imaging of support vector machine processing algorithm was used to clarify the outcome of maternal and neonatal gestational diabetes mellitus.

Methods: This study selected clinical data of 12,190 pregnant women who were hospitalized for delivery, and were divided into diabetic group (1268 cases) and control group (10922 cases) according to the diagnosis of gestational diabetes. The study was conducted from January 1, 2012 to December 31, 2019.

Learning Local-Global Multiple Correlation Filters for Robust Visual Tracking with Kalman Filter Redetection.

Visual object tracking is a significant technology for camera-based sensor networks applications. Multilayer convolutional features comprehensively used in correlation filter (CF)-based tracking algorithms have achieved excellent performance. However, there are tracking failures in some challenging situations because ordinary features are not able to well represent the object appearance variations and the correlation filters are updated irrationally.

Structural basis for guide RNA trimming by RNase D ribonuclease in Trypanosoma brucei.

Infection with kinetoplastid parasites, including Trypanosoma brucei (T. brucei), Trypanosoma cruzi (T. cruzi) and Leishmania can cause serious disease in humans.

Short DNA Oligonucleotide as a Ag Binding Detector.

Ag has been known to mediate several natural metallo-base pairs. Based on the unique structural information of a short 8-mer DNA strand (5'-GCACGCGC-3') induced by Ag, we constructed several fluorescent DNA beacons for the detection of Ag according to the increase in the fluorescence emission on Ag binding. This Ag detection assay is quick, sensitive, and easy to adapt and can function in a wide range of temperatures from 5 to 65 °C.

A unique DNA-binding mode of African swine fever virus AP endonuclease.

African swine fever virus (ASFV) is highly contagious and can cause lethal disease in pigs. ASFV is primarily replicated in the cytoplasm of pig macrophages, which is oxidative and caused constant damage to ASFV genome. ASFV AP endonuclease (AP) catalyzes DNA cleavage reaction at the abasic site and is a key enzyme of ASFV base excision repair (BER) system.

Structural studies reveal a ring-shaped architecture of deep-sea vent phage NrS-1 polymerase.

NrS-1 is the first known phage that can infect Epsilonproteobacteria, one of the predominant primary producers in the deep-sea hydrothermal vent ecosystems. NrS-1 polymerase is a multidomain enzyme and is one key component of the phage replisome. The N-terminal Prim/Pol and HBD domains are responsible for DNA polymerization and de novo primer synthesis activities of NrS-1 polymerase.

Structure of the error-prone DNA ligase of African swine fever virus identifies critical active site residues.

African swine fever virus (ASFV) is contagious and can cause highly lethal disease in pigs. ASFV DNA ligase (AsfvLIG) is one of the most error-prone ligases identified to date; it catalyzes DNA joining reaction during DNA repair process of ASFV and plays important roles in mutagenesis of the viral genome. Here, we report four AsfvLIG:DNA complex structures and demonstrate that AsfvLIG has a unique N-terminal domain (NTD) that plays critical roles in substrate binding and catalytic complex assembly.

Structural basis for multiple gene regulation by human DUX4.

DUX4 plays critical role in the molecular pathogenesis of the neuromuscular disorder facioscapulohumeral muscular dystrophy and acute lymphoblastic leukemia in humans. As a master transcription regulator, DUX4 can also bind the promoters and activate the transcription of hundreds ZGA-associated genes. Here we report on the structural and biochemical studies of DUX4 double homeodomains (DUX4-DH), representing the only structures contain both homeodomain 1 (HD1) and homeodomain 2 (HD2).

High-resolution DNA quadruplex structure containing all the A-, G-, C-, T-tetrads.

DNA can form diverse structures, which predefine their physiological functions. Besides duplexes that carry the genetic information, quadruplexes are the most well-studied DNA structures. In addition to their important roles in recombination, replication, transcription and translation, DNA quadruplexes have also been applied as diagnostic aptamers and antidisease therapeutics.

Structural insights into DNA degradation by human mitochondrial nuclease MGME1.

Mitochondrial nucleases play important roles in accurate maintenance and correct metabolism of mtDNA, the own genetic materials of mitochondria that are passed exclusively from mother to child. MGME1 is a highly conserved DNase that was discovered recently. Mutations in MGME1-coding gene lead to severe mitochondrial syndromes characterized by external ophthalmoplegia, emaciation, and respiratory failure in humans.

Structural insight into the role of VAL1 B3 domain for targeting to FLC locus in Arabidopsis thaliana.

Vernalization is a pivotal stage for some plants involving many epigenetic changes during cold exposure. In Arabidopsis, an essential step in vernalization for further flowering is successful silence the potent floral repressor Flowering Locus C (FLC) by repressing histone mark. AtVal1 is a multi-function protein containing five domains that participate into many recognition processes and is validated to recruit the repress histone modifier PHD-PRC2 complex and interact with components of the ASAP complex target to the FLC nucleation region through recognizing a cis element known as CME (cold memory element) by its plant-specific B3 domain.

Construction and structure studies of DNA-bipyridine complexes as versatile scaffolds for site-specific incorporation of metal ions into DNA.

The facile construction of metal-DNA complexes using 'Click' reactions is reported here. A series of 2'-propargyl-modified DNA oligonucleotides were initially synthesized as structure scaffolds and were then modified through 'Click' reaction to incorporate a bipyridine ligand equipped with an azido group. These metal chelating ligands can be placed in the DNA context in site-specific fashion to provide versatile templates for binding various metal ions, which are exchangeable using a simple EDTA washing-and-filtration step.

Molecular basis for the specific and multivariant recognitions of RNA substrates by human hnRNP A2/B1.

Human hnRNP A2/B1 is an RNA-binding protein that plays important roles in many biological processes, including maturation, transport, and metabolism of mRNA, and gene regulation of long noncoding RNAs. hnRNP A2/B1 was reported to control the microRNAs sorting to exosomes and promote primary microRNA processing as a potential mA "reader." hnRNP A2/B1 contains two RNA recognition motifs that provide sequence-specific recognition of RNA substrates.