Structural basis for flagellin-induced NAIP5 activation.

The NAIP (NLR family apoptosis inhibitory protein)/NLRC4 (NLR family CARD containing protein 4) inflammasome senses Gram-negative bacterial ligand. In the ligand-bound state, the winged helix domain of NAIP forms a steric clash with NLRC4 to open it up. However, how ligand binding activates NAIP is less clear.

Structural Determination of Glucosyltransferase C by Cryo-Electron Microscopy.

Biofilm formation is a critical factor in the development of cariogenic virulence of Streptococcus mutans. S. mutans has evolved a concerted mechanism to synthesize a biofilm matrix from dietary sugars by a family of glucosyltransferases (Gtfs).

Structural basis for flagellin induced NAIP5 activation.

The NAIP/NLRC4 inflammasome is activated when NAIP binds to a gram-negative bacterial ligand. Initially, NAIP exists in an inactive state with a wide-open conformation. Upon ligand binding, the winged helix domain (WHD) of NAIP is activated and forms steric clash with NLRC4 to open it up.

Mechanism of NAIP-NLRC4 inflammasome activation revealed by cryo-EM structure of unliganded NAIP5.

The nucleotide-binding domain (NBD), leucine rich repeat (LRR) domain containing protein family (NLR family) apoptosis inhibitory proteins (NAIPs) are cytosolic receptors that play critical roles in the host defense against bacterial infection. NAIPs interact with conserved bacterial ligands and activate the NLR family caspase recruitment domain containing protein 4 (NLRC4) to initiate the NAIP-NLRC4 inflammasome pathway. Here we found the process of NAIP activation is completely different from NLRC4.

Structural mechanisms of inflammasome regulation revealed by cryo-EM studies.

Inflammasomes are cytosolic protein complexes that form in response to pathogen or damage signals and initiate inflammation. Signal transduction in the inflammasome pathway occurs via protein-protein interaction, protein conformational change, and oligomerization. Recent advances in structural biology have provided multiple insights in inflammasome regulation that are both biologically intriguing and therapeutically valuable.

The Variability of Amino Acid Sequences in Hepatitis B Virus.

Hepatitis B virus (HBV) is an important human pathogen belonging to the Hepadnaviridae family, Orthohepadnavirus genus. Over 240 million people are infected with HBV worldwide. The reverse transcription during its genome replication leads to low fidelity DNA synthesis, which is the source of variability in the viral proteins.

Cryo-EM structure of native spherical subviral particles isolated from HBV carriers.

Hepatitis B virus (HBV) contains 3 types of particles, i.e., 22-nm-diameter spherical and tubular subviral particles (SVPs) and 44-nm-diameter Dane particles.

Structure determination of a human virus by the combination of cryo-EM and X-ray crystallography.

Virus 3D atomic structures provide insight into our understanding of viral life cycles and the development of antiviral drugs. X-ray crystallography and cryo-EM have been used to determine the atomic structure of viruses. However, limited availability of biological samples, biosafety issues due to virus infection, and sometimes inherent characteristics of viruses, pose difficulties on combining both methods in determining viral structures.

Characterization of the VP39 envelope protein from Singapore grouper iridovirus.

Singapore grouper iridovirus (SGIV) is a major pathogen that causes heavy economic losses to the grouper aquaculture industry in China and Southeast Asian countries. In the present study, a viral envelope protein, VP39, encoded by SGIV ORF39L, was identified and characterized. SGIV ORF39L was found in all sequenced iridoviruses and is now considered to be a core gene of the family Iridoviridae.

Proteomic analysis of Singapore grouper iridovirus envelope proteins and characterization of a novel envelope protein VP088.

Singapore grouper iridovirus (SGIV) is an enveloped virus causing heavy economic losses to marine fish culture. The envelope fractions of SGIV were separated from the purified virions by Triton X-100 treatment, and subjected to 1-DE-MALDI-TOF/TOF-MS/MS and LC-MALDI-TOF/TOF-MS/MS analysis. A total of 19 virus-encoded envelope proteins were identified in this study and 73.

Characterization of Singapore grouper iridovirus (SGIV) ORF086R, a putative homolog of ICP18 involved in cell growth control and virus replication.

Singapore grouper iridovirus (SGIV), as a causative agent of serious systemic disease, causes significant economic losses in grouper aquaculture. In this study, a novel ICP18 homolog encoded by SGIV ORF086R was identified and characterized. Strikingly, ICP18 homologs can be found in all ranaviruses, but not in other sequenced large DNA viruses.

Complete sequence determination of a novel reptile iridovirus isolated from soft-shelled turtle and evolutionary analysis of Iridoviridae.

Background: Soft-shelled turtle iridovirus (STIV) is the causative agent of severe systemic diseases in cultured soft-shelled turtles (Trionyx sinensis). To our knowledge, the only molecular information available on STIV mainly concerns the highly conserved STIV major capsid protein. The complete sequence of the STIV genome is not yet available.