The structure of MucD from Pseudomonas syringae revealed N-terminal loop-mediated trimerization of HtrA-like serine protease.

Protein quality control mechanisms are essential for maintaining cellular integrity, and the HtrA family of serine proteases plays a crucial role in handling folding stress in prokaryotic periplasm. Escherichia coli harbors three HtrA members, namely, DegS, DegP, and DegQ, which share a common domain structure. MucD, a putative HtrA family member that resembles DegP, is involved in alginate biosynthesis regulation and the stress response.

Structural basis of DNA binding by the NAC transcription factor ORE1, a master regulator of plant senescence.

Plants use sophisticated mechanisms of gene expression to control senescence in response to environmental stress or aging. ORE1 (Arabidopsis thaliana NAC092) is a master regulator of senescence that belongs to the plant-specific NAC transcription factor protein family. ORE1 has been reported to bind to multiple DNA targets to orchestrate leaf senescence, yet the mechanistic basis for recognition of the cognate gene sequence remains unclear.

Molecular basis of dual anti-CRISPR and auto-regulatory functions of AcrIF24.

CRISPR-Cas systems are adaptive immune systems in bacteria and archaea that provide resistance against phages and other mobile genetic elements. To fight against CRISPR-Cas systems, phages and archaeal viruses encode anti-CRISPR (Acr) proteins that inhibit CRISPR-Cas systems. The expression of acr genes is controlled by anti-CRISPR-associated (Aca) proteins encoded within acr-aca operons.

BL-11C Micro-MX: a high-flux microfocus macromolecular-crystallography beamline for micrometre-sized protein crystals at Pohang Light Source II.

BL-11C, a new protein crystallography beamline, is an in-vacuum undulator-based microfocus beamline used for macromolecular crystallography at the Pohang Accelerator Laboratory and it was made available to users in June 2017. The beamline is energy tunable in the range 5.0-20 keV to support conventional single- and multi-wavelength anomalous-dispersion experiments against a wide range of heavy metals.

Upgrade of BL-5C as a highly automated macromolecular crystallography beamline at Pohang Light Source II.

BL-5C is an in-vacuum undulator beamline dedicated to macromolecular crystallography (MX) at the 3 GeV Pohang Light Source II in Korea. The beamline delivers X-ray beams with a focal spot size of 200 µm × 40 µm (FWHM, H × V) over the energy range 6.5-16.

Molecular basis of IRGB10 oligomerization and membrane association for pathogen membrane disruption.

Immunity-related GTPase B10 (IRGB10) belongs to the interferon (IFN)-inducible GTPases, a family of proteins critical to host defense. It is induced by IFNs after pathogen infection, and plays a role in liberating pathogenic ligands for the activation of the inflammasome by directly disrupting the pathogen membrane. Although IRGB10 has been intensively studied owing to its functional importance in the cell-autonomous immune response, the molecular mechanism of IRGB10-mediated microbial membrane disruption is still unclear.

A therapeutic neutralizing antibody targeting receptor binding domain of SARS-CoV-2 spike protein.

Vaccines and therapeutics are urgently needed for the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we screen human monoclonal antibodies (mAb) targeting the receptor binding domain (RBD) of the viral spike protein via antibody library constructed from peripheral blood mononuclear cells of a convalescent patient. The CT-P59 mAb potently neutralizes SARS-CoV-2 isolates including the D614G variant without antibody-dependent enhancement effect.

Crystal structure of PYCH_01220 from Pyrococcus yayanosii potentially involved in binding nucleic acid.

We report the crystal structure of PYCH_01220, a hypothetical protein in Pyrococcus yayanosii CH1. This protein is composed of two domains, named Domain A and Domain B. While Domain B is not significantly homologous to known protein structures, Domain A is structurally analogous to the C-terminal ribonuclease domain of Escherichia coli colicin D.

Wide-open conformation of UDP-MurNc-tripeptide ligase revealed by the substrate-free structure of MurE from Acinetobacter baumannii.

MurE ligase catalyzes the attachment of meso-diaminopimelic acid to the UDP-MurNAc- -Ala- -Glu using ATP and producing UDP-MurNAc- -Ala- -Glu-meso-A pm during bacterial cell wall biosynthesis. Owing to the critical role of this enzyme, MurE is considered an attractive target for antibacterial drugs. Despite extensive studies on MurE ligase, the structural dynamics of its conformational changes are still elusive.

A 1.3 Å high-resolution crystal structure of an anti-CRISPR protein, AcrI E2.

As a result of bacterial infection with viruses, bacteria have developed CRISPR-Cas as an adaptive immune system, which allows them to destroy the viral genetic material introduced via infection. However, viruses have also evolved to develop multiple anti-CRISPR proteins, which are capable of inactivating the CRISPR-Cas adaptive immune system to combat bacteria. In this study, we aimed to elucidate the molecular mechanisms associated with anti-CRISPR proteins by determining a high-resolution crystal structure (1.

Structural Basis for Broad Substrate Selectivity of Alcohol Dehydrogenase YjgB from .

In metabolic engineering and synthetic biology fields, there have been efforts to produce variable bioalcohol fuels, such as isobutanol and 2-phenylethanol, in order to meet industrial demands. YjgB is an aldehyde dehydrogenase from Escherichia coli that shows nicotinamide adenine dinucleotide phosphate (NADP)-dependent broad selectivity for aldehyde derivatives with an aromatic ring or small aliphatic chain. This could contribute to the design of industrial synthetic pathways.

Evidence for binary Smc complexes lacking kite subunits in archaea.

SMC complexes play a central role in chromosome organization in all domains of life. The bacterial Smc-ScpAB complex is a three-subunit complex composed of Smc, ScpA and ScpB. ScpA bridges the two ATPase domains of the Smc homodimer, while ScpB, which belongs to the kite family of proteins, interacts with ScpA.

Structural transformation-mediated dimerization of caspase recruitment domain revealed by the crystal structure of CARD-only protein in frog virus 3.

Caspase recruitment domain (CARD)-only proteins (COPs), regulate apoptosis, inflammation, and innate immunity. They inhibit the assembly of NOD-like receptor complexes such as the inflammasome and NODosome, which are molecular complexes critical for caspase-1 activation. COPs are known to interact with either caspase-1 CARD or RIP2 CARD via a CARD-CARD interaction, and inhibit caspase-1 activation or further downstream signaling.

Crystal Structures of Penicillin-Binding Protein D2 from Listeria monocytogenes and Structural Basis for Antibiotic Specificity.

β-Lactam antibiotics that inhibit penicillin-binding proteins (PBPs) have been widely used in the treatment of bacterial infections. However, the molecular basis underlying the different inhibitory potencies of β-lactams against specific PBPs is not fully understood. Here, we present the crystal structures of penicillin-binding protein D2 (PBPD2) from , a Gram-positive foodborne bacterial pathogen that causes listeriosis in humans.

Crystal structure of Arabidopsis thaliana RabA1a.

RabGTPase is a member of the Ras superfamily of small GTPases, which share a GTP-binding pocket containing highly conserved motifs that promote GTP hydrolysis. In Arabidopsis, the RabA group, which corresponds to the Rab11 group in animals, functions in the recycling of endosomes that control docking and fusion during vesicle transport. However, their molecular mechanisms remain unknown.

Architecture of the type IV coupling protein complex of Legionella pneumophila.

Many bacteria, including Legionella pneumophila, rely on the type IV secretion system to translocate a repertoire of effector proteins into the hosts for their survival and growth. Type IV coupling protein (T4CP) is a hexameric ATPase that links translocating substrates to the transenvelope secretion conduit. Yet, how a large number of effector proteins are selectively recruited and processed by T4CPs remains enigmatic.

CIDE domains form functionally important higher-order assemblies for DNA fragmentation.

Cell death-inducing DFF45-like effector (CIDE) domains, initially identified in apoptotic nucleases, form a family with diverse functions ranging from cell death to lipid homeostasis. Here we show that the CIDE domains of and human apoptotic nucleases Drep2, Drep4, and DFF40 all form head-to-tail helical filaments. Opposing positively and negatively charged interfaces mediate the helical structures, and mutations on these surfaces abolish nuclease activation for apoptotic DNA fragmentation.

Identification of a Highly Conserved Hypothetical Protein TON_0340 as a Probable Manganese-Dependent Phosphatase.

A hypothetical protein TON_0340 of a Thermococcus species is a protein conserved in a variety of organisms including human. Herein, we present four different crystal structures of TON_0340, leading to the identification of an active-site cavity harboring a metal-binding site composed of six invariant aspartate and glutamate residues that coordinate one to three metal ions. Biochemical and mutational analyses involving many phosphorous compounds show that TON_0340 is a Mn2+-dependent phosphatase.

Crystal Structure of C-Terminal Coiled-Coil Domain of SYCP1 Reveals Non-Canonical Anti-Parallel Dimeric Structure of Transverse Filament at the Synaptonemal Complex.

The synaptonemal complex protein 1 (SYCP1) is the main structural element of transverse filaments (TFs) of the synaptonemal complex (SC), which is a meiosis-specific complex structure formed at the synapse of homologue chromosomes to hold them together. The N-terminal domain of SYCP1 is known to be located within the central elements (CEs), whereas the C-terminal domain is located toward lateral elements (LEs). SYCP1 is a well-known meiosis marker that is also known to be a prognostic marker in the early stage of several cancers including breast, gliomas, and ovarian cancers.

Crystal structures of Dronpa complexed with quenchable metal ions provide insight into metal biosensor development.

Many fluorescent proteins (FPs) show fluorescence quenching by specific metal ions, which can be applied towards metal biosensor development. In this study, we investigated the significant fluorescence quenching of Dronpa by Co(2+) and Cu(2+) ions. Crystal structures of Co(2+) -, Ni(2+) - and Cu(2+) -bound Dronpa revealed previously unseen, unique, metal-binding sites for fluorescence quenching.

GC1118, an Anti-EGFR Antibody with a Distinct Binding Epitope and Superior Inhibitory Activity against High-Affinity EGFR Ligands.

The EGFR-targeted monoclonal antibodies are a valid therapeutic strategy for patients with metastatic colorectal cancer (mCRC). However, only a small subset of mCRC patients has therapeutic benefits and there are high demands for EGFR therapeutics with a broader patient pool and more potent efficacy. In this study, we report GC1118 exhibiting a different character in terms of binding epitope, affinity, mode of action, and efficacy from other anti-EGFR antibodies.

Assembly of Multi-tRNA Synthetase Complex via Heterotetrameric Glutathione Transferase-homology Domains.

Many multicomponent protein complexes mediating diverse cellular processes are assembled through scaffolds with specialized protein interaction modules. The multi-tRNA synthetase complex (MSC), consisting of nine different aminoacyl-tRNA synthetases and three non-enzymatic factors (AIMP1-3), serves as a hub for many signaling pathways in addition to its role in protein synthesis. However, the assembly process and structural arrangement of the MSC components are not well understood.

Crystal structure of caspase recruiting domain (CARD) of apoptosis repressor with CARD (ARC) and its implication in inhibition of apoptosis.

Apoptosis repressor with caspase recruiting domain (ARC) is a multifunctional inhibitor of apoptosis that is unusually over-expressed or activated in various cancers and in the state of the pulmonary hypertension. Therefore, ARC might be an optimal target for therapeutic intervention. Human ARC is composed of two distinct domains, N-terminal caspase recruiting domain (CARD) and C-terminal P/E (proline and glutamic acid) rich domain.

Molecular basis for SMC rod formation and its dissolution upon DNA binding.

SMC condensin complexes are central modulators of chromosome superstructure in all branches of life. Their SMC subunits form a long intramolecular coiled coil, which connects a constitutive "hinge" dimerization domain with an ATP-regulated "head" dimerization module. Here, we address the structural arrangement of the long coiled coils in SMC complexes.