Evidence for dynamic in vivo interconversion of the conformational states of IscU during iron-sulfur cluster biosynthesis.

IscU is a central component of the ISC machinery and serves as a scaffold for de novo assembly of Fe-S clusters. The dedicated chaperone system composed of the Hsp70-chaperone HscA and the J-protein cochaperone HscB synergistically interacts with IscU and facilitates cluster transfer from IscU to recipient apo-proteins. Here, we report that the otherwise essential roles of HscA and HscB can be bypassed in vivo by a number of single amino acid substitutions in IscU.

High Production of Ergothioneine in using the Sulfoxide Synthase from strains.

We previously constructed a heterologous production system for ergothioneine (ERG) in using five ERG biosynthesis genes () from . However, significant amounts of hercynine (HER), an intermediate of ERG, as ERG were accumulated, suggesting that the reaction of EgtB catalyzing the attachment of γ-glutamylcysteine (γGC) to HER to yield hercynyl-γ-glutamylcysteine sulfoxide was a bottleneck. In this study, we searched for other EgtBs and found many orthologs in diverse microorganisms.

Transcatheter aortic valve implantation after aortic valve neocuspidization using autologous pericardium: a case report.

Background: Aortic valve neocuspidization (AVNeo), a novel surgical procedure used in the treatment of aortic valve diseases, including aortic stenosis (AS), involves the replacement of three aortic valve cusps by glutaraldehyde-treated autologous pericardium. Although reoperation risk is low, no case report on the deterioration of the AVNeo has yet been published.

Case Summary: An 80-year-old woman who underwent AVNeo for severe degenerative tricuspid AS 6 years previously complained of shortness of breath.

Identification of IscU residues critical for de novo iron-sulfur cluster assembly.

IscU is a central component of the ISC machinery and serves as a scaffold for the de novo assembly of iron-sulfur (Fe-S) clusters prior to their delivery to target apo-Fe-S proteins. However, the molecular mechanism is not yet fully understood. In this study, we have conducted mutational analysis of E.

Generation of hydrogen sulfide from sulfur assimilation in Escherichia coli.

Many organisms produce endogenous hydrogen sulfide (HS) as a by-product of protein, peptide, or L-cysteine degradation. Recent reports concerning mammalian cells have demonstrated that HS acts as a signaling molecule playing important roles in various biological processes. In contrast to mammals, bacterial HS signaling remains unclear.

Gram-scale fermentative production of ergothioneine driven by overproduction of cysteine in Escherichia coli.

Ergothioneine (ERG), a unique thiol compound, is suggested to function as an antioxidant and cytoprotectant. Despite several recent attempts to produce ERG using various organisms, its yield was still very low and the costs remained high. Since the level of ERG produced depends strictly on the availability of three distinct precursor amino acids (L-cysteine (Cys), L-histidine, and L-methionine (Met)), metabolic engineering for enhancement of the flux toward ERG biosynthesis is required.

Distinct roles for U-type proteins in iron-sulfur cluster biosynthesis revealed by genetic analysis of the Bacillus subtilis sufCDSUB operon.

The biosynthesis of iron-sulfur (Fe-S) clusters in Bacillus subtilis is mediated by the SUF-like system composed of the sufCDSUB gene products. This system is unique in that it is a chimeric machinery comprising homologues of E. coli SUF components (SufS, SufB, SufC and SufD) and an ISC component (IscU).

Mapping the key residues of SufB and SufD essential for biosynthesis of iron-sulfur clusters.

Biogenesis of iron-sulfur (Fe-S) clusters is an indispensable process in living cells. In Escherichia coli, the SUF biosynthetic system consists of six proteins among which SufB, SufC and SufD form the SufBCD complex, which serves as a scaffold for the assembly of nascent Fe-S cluster. Despite recent progress in biochemical and structural studies, little is known about the specific regions providing the scaffold.

Improved fermentative L-cysteine overproduction by enhancing a newly identified thiosulfate assimilation pathway in Escherichia coli.

Sulfate (SO) is an often-utilized and well-understood inorganic sulfur source in microorganism culture. Recently, another inorganic sulfur source, thiosulfate (SO), was proposed to be more advantageous in microbial growth and biotechnological applications. Although its assimilation pathway is known to depend on O-acetyl-L-serine sulfhydrylase B (CysM in Escherichia coli), its metabolism has not been extensively investigated.

Novel features of the ISC machinery revealed by characterization of Escherichia coli mutants that survive without iron-sulfur clusters.

Biological assembly of iron-sulfur (Fe-S) clusters is mediated by complex systems consisting of multiple proteins. Escherichia coli possesses two distinct systems called the ISC and SUF machineries encoded by iscSUA-hscBA-fdx-iscX and sufABCDSE respectively. Deletion of both pathways results in absence of the biosynthetic apparatus for Fe-S clusters, and consequent lethality, which has hampered detailed genetic studies.

Functional Dynamics Revealed by the Structure of the SufBCD Complex, a Novel ATP-binding Cassette (ABC) Protein That Serves as a Scaffold for Iron-Sulfur Cluster Biogenesis.

ATP-binding cassette (ABC)-type ATPases are chemomechanical engines involved in diverse biological pathways. Recent genomic information reveals that ABC ATPase domains/subunits act not only in ABC transporters and structural maintenance of chromosome proteins, but also in iron-sulfur (Fe-S) cluster biogenesis. A novel type of ABC protein, the SufBCD complex, functions in the biosynthesis of nascent Fe-S clusters in almost all Eubacteria and Archaea, as well as eukaryotic chloroplasts.

Immunolocalization of 8-5' and 8-8' linked structures of lignin in cell walls of Chamaecyparis obtusa using monoclonal antibodies.

Mouse monoclonal antibodies were generated against dehydrodiconiferyl alcohol- or pinoresinol-p-aminohippuric acid (pAHA)-bovine serum albumin (BSA) conjugate as probes that specifically react with 8-5' or 8-8' linked structure of lignin in plant cell walls. Hybridoma clones were selected that produced antibodies that positively reacted with dehydrodiconiferyl alcohol- or pinoresinol-pAHA-BSA and negatively reacted with pAHA-BSA and guaiacylglycerol-beta-guaiacyl ether-pAHA-BSA conjugates containing 8-O-4' linkage. Eight clones were established for each antigen and one of each clone that positively reacted with wood sections was selected.