The N-terminal region of Jaw1 has a role to inhibit the formation of organized smooth endoplasmic reticulum as an intrinsically disordered region

Jaw1/LRMP is a type II integral membrane protein that is localized at the endoplasmic reticulum (ER) and outer nuclear membrane. We previously reported that a function of Jaw1 is to maintain the nuclear shape as a KASH protein via its carboxyl terminal region, a component of linker of nucleoskeleton and cytoskeleton complex in the oligomeric state. Although the oligomerization of some KASH proteins via the cytosolic regions serves to stabilize protein-protein interactions, the issue of how the oligomerization of Jaw1 is regulated is not completely understood. Therefore, we focused on three distinct regions on the cytosolic face of Jaw1: the N-terminal region, the coiled-coil domain and the stem region, in terms of oligomerization. A co-immunoprecipitation assay showed that its coiled-coil domain is a candidate for the oligomerization site. Furthermore, our data indicated that the N-terminal region prevents the aberrant oligomerization of Jaw1 as an intrinsically disordered region (IDR). Importantly, the ectopic expression of an N-terminal region deleted mutant caused the formation of organized smooth ER (OSER), structures such as nuclear karmellae and whorls, in B16F10 cells. Furthermore, this OSER interfered with the localization of the oligomer and interactors such as the type III inositol 1,4,5-triphosphate receptor (IP3R3) and SUN2. In summary, the N-terminal region of Jaw1 inhibits the formation of OSER as an IDR to maintain the homeostatic localization of interactors on the ER membrane

Bacteroidota polysaccharide utilization system for branched dextran exopolysaccharides from lactic acid bacteria

publishe

Bacteroidota polysaccharide utilization system for branched dextran exopolysaccharides from lactic acid bacteria

publishe

Crystallization and preliminary X-ray analysis of Thermoactinomyces vulgaris R-47 maltooligosaccharide-metabolizing enzyme homologous to glucoamylase

A maltooligosaccharide-metabolizing enzyme from T. vulgaris R-47 (TGA) homologous to glucoamylase degrades maltooligosaccharides more efficiently than starch, unlike fungal glucoamylases. TGA was crystallized and the state of the protein in solution was analyzed by gel-filtration chromatography

Heterologous expression, crystallization and preliminary X-ray characterization of CcCel6C, a glycoside hydrolase family 6 enzyme from the basidiomycete Coprinopsis cinerea

Crystallization of CcCel6C was carried out by the hanging-drop vapour-diffusion method. X-ray diffraction data were collected to 1.6 Å resolution from the crystal

Characterization of fructooligosaccharide metabolism and fructooligosaccharide-degrading enzymes in human commensal butyrate producers

Butyrate produced by gut microbiota has multiple beneficial effects on host health, and oligosaccharides derived from host diets and glycans originating from host mucus are major sources of its production. A significant reduction of butyrate-producing bacteria has been reported in patients with inflammatory bowel diseases and colorectal cancers. Although gut butyrate levels are important for host health, oligosaccharide metabolic properties in butyrate producers are poorly characterized. We studied the metabolic properties of fructooligosaccharides (FOSs) and other prebiotic oligosaccharides (i.e. raffinose and xylooligosaccharides; XOSs) in gut butyrate producers. 1-Kestose (kestose) and nystose, FOSs with degrees of polymerization of 3 and 4, respectively, were also included. Fourteen species of butyrate producers were divided into four groups based on their oligosaccharide metabolic properties, which are group A (two species) metabolizing all oligosaccharides tested, group F (four species) metabolizing FOSs but not raffinose and XOSs, group XR (four species) metabolizing XOSs and/or raffinose but not FOSs, and group N (four species) metabolizing none of the oligosaccharides tested. Species assigned to groups A and XR are rich glycoside hydrolase (GH) holders, whereas those in groups F and N are the opposite. In total, 17 enzymes assigned to GH32 were observed in nine of the 14 butyrate producers tested, and species that metabolized FOSs had at least one active GH32 enzyme. The GH32 enzymes were divided into four clusters by phylogenetic analysis. Heterologous gene expression analysis revealed that the GH32 enzymes in each cluster had similar FOS degradation properties within clusters, which may be linked to the conservation/substitution of amino acids to bind with substrates in GH32 enzymes. This study provides important knowledge to understand the impact of FOS supplementation on the activation of gut butyrate producers. Abbreviations: SCFA, short chain fatty acid; FOS, fructooligosaccharide; XOS, xylooligosaccharide; CAZy, Carbohydrate Active Enzymes; CBM, carbohydrate-binding module; PUL, polysaccharide utilization locus; S6PH sucrose-6-phosphate hydrolase

Carbohydrate recognition mechanism of HA70 from Clostridium botulinum deduced from X-ray structures in complexes with sialylated oligosaccharides

AbstractClostridium botulinum produces the botulinum neurotoxin, forming a large complex as progenitor toxins in association with non-toxic non-hemagglutinin and/or several different hemagglutinin (HA) subcomponents, HA33, HA17 and HA70, which bind to carbohydrate of glycoproteins from epithelial cells in the infection process. To elucidate the carbohydrate recognition mechanism of HA70, X-ray structures of HA70 from type C toxin (HA70/C) in complexes with sialylated oligosaccharides were determined, and a binding assay by the glycoconjugate microarray was performed. These results suggested that HA70/C can recognize both α2–3- and α2–6-sialylated oligosaccharides, and that it has a higher affinity for α2–3-sialylated oligosaccharides