scholarly journals The disulfide oxidoreductase SdbA is active inStreptococcus gordoniiusing a single C-terminal cysteine of the CXXC motif

2015 ◽  
Vol 99 (2) ◽  
pp. 236-253 ◽  
Author(s):  
Lauren Davey ◽  
Alejandro Cohen ◽  
Jason LeBlanc ◽  
Scott A. Halperin ◽  
Song F. Lee
Keyword(s):  
Cxxc Motif ◽  
Disulfide Oxidoreductase

scholarly journals Identification of a Thiol-Disulfide Oxidoreductase (SdbA) catalyzing Disulfide Bond Formation in the Superantigen SpeA in Streptococcus pyogenes

2021 ◽  
Author(s):  
Song F. Lee ◽  
Lydia Li ◽  
Naif Jalal ◽  
Scott A. Halperin
Keyword(s):  
Streptococcus Pyogenes ◽  
Disulfide Bond ◽  
Biological Activities ◽  
Bond Formation ◽  
Site Directed Mutagenesis ◽  
Cysteine Residues ◽  
Initial Reaction ◽  
Disulfide Bond Formation ◽  
Cxxc Motif ◽  
Disulfide Oxidoreductase

Mechanisms of disulfide bond formation in the human pathogen Streptococcus pyogenes is currently unknown. To date, no disulfide bond forming thiol-disulfide oxidoreductase (TDOR) has been described and at least one disulfide bonded protein is known in S. pyogenes . This protein is the superantigen SpeA, which contains 3 cysteine residues (Cys 87, Cys90, and Cys98), and has a disulfide bond is formed between Cys87 and Cys98. In this study, candidate TDORs were identified from the genome seuence of S. pyogenes MGAS8232. Using mutational and biochemical approaches, one of the candidate proteins, SpyM18_2037 (named here SdbA), was shown to be the catalyst that introduces the disulfide bond in SpeA. SpeA in the culture supernatant remained reduced when sdbA was inactivated and restored to the oxidized state when a functional copy of sdbA was returned to the sdbA -knockout mutant. SdbA has a typical C 46 XXC 49 active site motif commonly found in TDORs. Site-directed mutagenesis experiments showed that the cysteines in the CXXC motif were required the disulfide bond in SpeA to form. Interactions between SdbA and SpeA were examined using cysteine variant proteins. The results showed that SdbA C49A formed a mixed disulfide with SpeA C87A , suggesting that the N-terminal Cys46 of SdbA and the C-terminal Cys98 of SpeA participated in the initial reaction. SpeA oxidized by SdbA displayed biological activities suggesting that SpeA was properly folded following oxidation by SdbA. In conclusion, formation of the disulfide bond in SpeA is catalyzed by SdbA and the findings represent the first report of disulfide bond formation in S. pyogenes . IMPORTANCE Here, we reported the first example of disulfide bond formation in Streptococcus pyogenes . The results showed that a thiol-disulfide oxidoreductase, named SdbA, is responsible for introducing the disulfide bond in the superantigen SpeA. The cysteine residues in the CXXC motif of SdbA are needed for catalyzing the disulfide bond in SpeA. The disulfide bond in SpeA and neighboring amino acids form a disulfide loop that is conserved among many superantigens, including those from Staphylococcus aureus . SpeA and staphylococcal enterotoxins lacking the disulfide bond are biologically inactive. Thus, the discovery of the enzyme that catalyzes the disulfide bond in SpeA is important to understanding the biochemistry of SpeA production and presents a target for mitigating the virulence of S. pyogenes .

scholarly journals Activation of choleragen by thiol: protein disulfide oxidoreductase.

1980 ◽  
Vol 255 (23) ◽  
pp. 11085-11087
Author(s):  
J. Moss ◽  
S.J. Stanley ◽  
J.E. Morin ◽  
J.E. Dixon
Keyword(s):  
Protein Disulfide Oxidoreductase ◽  
Disulfide Oxidoreductase ◽  
Protein Disulfide ◽  
Thiol Protein

Insights on a New PDI-like Family: Structural and Functional Analysis of a Protein Disulfide Oxidoreductase from the Bacterium Aquifex aeolicus

2006 ◽  
Vol 356 (1) ◽  
pp. 155-164 ◽  
Author(s):  
Emilia Pedone ◽  
Katia D'Ambrosio ◽  
Giuseppina De Simone ◽  
Mosè Rossi ◽  
Carlo Pedone ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Aquifex Aeolicus ◽  
Protein Disulfide Oxidoreductase ◽  
Disulfide Oxidoreductase ◽  
Protein Disulfide

scholarly journals Structural and Biochemical Characterization of Thioredoxin-2 from Deinococcus radiodurans

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1843
Author(s):  
Min-Kyu Kim ◽  
Lei Zhao ◽  
Soyoung Jeong ◽  
Jing Zhang ◽  
Jong-Hyun Jung ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Active Site ◽  
Biochemical Characterization ◽  
Deinococcus Radiodurans ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Antioxidant Systems ◽  
Zinc Finger Domain ◽  
Cxxc Motif ◽  
Reduction Activity ◽  
Trx Fold

Thioredoxin (Trx), a ubiquitous protein showing disulfide reductase activity, plays critical roles in cellular redox control and oxidative stress response. Trx is a member of the Trx system, comprising Trx, Trx reductase (TrxR), and a cognate reductant (generally reduced nicotinamide adenine dinucleotide phosphate, NADPH). Bacterial Trx1 contains only the Trx-fold domain, in which the active site CXXC motif that is critical for the disulfide reduction activity is located. Bacterial Trx2 contains an N-terminal extension, which forms a zinc-finger domain, including two additional CXXC motifs. The multi-stress resistant bacterium Deinococcus radiodurans encodes both Trx1 (DrTrx1) and Trx2 (DrTrx2), which act as members of the enzymatic antioxidant systems. In this study, we constructed Δdrtrx1 and Δdrtrx2 mutants and examined their survival rates under H2O2 treated conditions. Both drtrx1 and drtrx2 genes were induced following H2O2 treatment, and the Δdrtrx1 and Δdrtrx2 mutants showed a decrease in resistance toward H2O2, compared to the wild-type. Native DrTrx1 and DrTrx2 clearly displayed insulin and DTNB reduction activity, whereas mutant DrTrx1 and DrTrx2, which harbors the substitution of conserved cysteine to serine in its active site CXXC motif, showed almost no reduction activity. Mutations in the zinc binding cysteines did not fully eliminate the reduction activities of DrTrx2. Furthermore, we solved the crystal structure of full-length DrTrx2 at 1.96 Å resolution. The N-terminal zinc-finger domain of Trx2 is thought to be involved in Trx-target interaction and, from our DrTrx2 structure, the orientation of the zinc-finger domain of DrTrx2 and its interdomain interaction, between the Trx-fold domain and the zinc-finger domain, is clearly distinguished from those of the other Trx2 structures.

scholarly journals EDEM2 stably disulfide-bonded to TXNDC11 catalyzes the first mannose trimming step in mammalian glycoprotein ERAD

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ginto George ◽  
Satoshi Ninagawa ◽  
Hirokazu Yagi ◽  
Taiki Saito ◽  
Tokiro Ishikawa ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Gene Knockout ◽  
Covalent Bonding ◽  
Cxxc Motif ◽  
Endoplasmic Reticulum Associated Degradation ◽  
Endoplasmic Reticulum Protein ◽  
Hct116 Cells

Sequential mannose trimming of N-glycan (Man9GlcNAc2 -> Man8GlcNAc2 -> Man7GlcNAc2) facilitates endoplasmic reticulum-associated degradation of misfolded glycoproteins (gpERAD). Our gene knockout experiments in human HCT116 cells have revealed that EDEM2 is required for the first step. However, it was previously shown that purified EDEM2 exhibited no α1,2-mannosidase activity toward Man9GlcNAc2 in vitro. Here, we found that EDEM2 was stably disulfide-bonded to TXNDC11, an endoplasmic reticulum protein containing five thioredoxin (Trx)-like domains. C558 present outside of the mannosidase homology domain of EDEM2 was linked to C692 in Trx5, which solely contains the CXXC motif in TXNDC11. This covalent bonding was essential for mannose trimming and subsequent gpERAD in HCT116 cells. Furthermore, EDEM2-TXNDC11 complex purified from transfected HCT116 cells converted Man9GlcNAc2 to Man8GlcNAc2(isomerB) in vitro. Our results establish the role of EDEM2 as an initiator of gpERAD, and represent the first clear demonstration of in vitro mannosidase activity of EDEM family proteins.

scholarly journals A Disulfide Oxidoreductase (CHU_1165) Is Essential for Cellulose Degradation by Affecting Outer Membrane Proteins in Cytophaga hutchinsonii

2020 ◽  
Vol 86 (8) ◽  
Author(s):  
Dong Zhao ◽  
Ying Wang ◽  
Sen Wang ◽  
Weican Zhang ◽  
Qingsheng Qi ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Disulfide Bond ◽  
Cellulose Degradation ◽  
Outer Membrane Proteins ◽  
Hypothetical Protein ◽  
Pleiotropic Effect ◽  
Content Type ◽  
Cytophaga Hutchinsonii ◽  
Disulfide Oxidoreductase

ABSTRACT Cytophaga hutchinsonii cells can bind to the surface of insoluble cellulose and degrade it by utilizing a novel cell contact-dependent mechanism, in which the outer membrane proteins may play important roles. In this study, the deletion of a gene locus, chu_1165, which encodes a hypothetical protein with 32% identity with TlpB, a disulfide oxidoreductase in Flavobacterium psychrophilum, caused a complete cellulolytic defect in C. hutchinsonii. Further study showed that cells of the Δ1165 strain could not bind to cellulose, and the levels of many outer membrane proteins that can bind to cellulose were significantly decreased. The N-terminal region of CHU_1165 is anchored to the cytoplasmic membrane with five predicted transmembrane helices, and the C-terminal region is predicted to stretch to the periplasm and has a similar thioredoxin (Trx) fold containing a Cys-X-X-Cys motif that is conserved in disulfide oxidoreductases. Recombinant CHU_1165His containing the Cys-X-X-Cys motif was able to reduce the disulfide bonds of insulin in vitro. Site-directed mutation showed that the cysteines in the Cys-X-X-Cys motif and at residues 106 and 108 were indispensable for the function of CHU_1165. Western blotting showed that CHU_1165 was in an oxidized state in vivo, suggesting that it may act as an oxidase to catalyze disulfide bond formation. However, many of the decreased outer membrane proteins that were essential for cellulose degradation contained no or one cysteine, and mutation of the cysteine in these proteins did not affect cellulose degradation, indicating that CHU_1165 may have an indirect or pleiotropic effect on the function of these outer membrane proteins. IMPORTANCE Cytophaga hutchinsonii can rapidly digest cellulose in a contact-dependent manner, in which the outer membrane proteins may play important roles. In this study, a hypothetical protein, CHU_1165, characterized as a disulfide oxidoreductase, is essential for cellulose degradation by affecting the cellulose binding ability of many outer membrane proteins in C. hutchinsonii. Disulfide oxidoreductases are involved in disulfide bond formation. However, our studies show that many of the decreased outer membrane proteins that were essential for cellulose degradation contained no or one cysteine, and mutation of cysteine did not affect their function, indicating that CHU_1165 did not facilitate the formation of a disulfide bond in these proteins. It may have an indirect or pleiotropic effect on the function of these outer membrane proteins. Our study provides an orientation for exploring the proteins that assist in the appropriate conformation of many outer membrane proteins essential for cellulose degradation, which is important for exploring the novel mechanism of cellulose degradation in C. hutchinsonii.

scholarly journals La myopathie liée à PYROXD1: Caractérisation clinique, histologique, et génétique

2019 ◽  
Vol 35 ◽  
pp. 43-44
Author(s):  
Xavière Lornage ◽  
Norma B. Romero ◽  
Jocelyn Laporte ◽  
Johann Böhm
Keyword(s):  
Pyridine Nucleotide ◽  
Stress Oxydatif ◽  
Disulfide Oxidoreductase

Des mutations récessives dans le gène PYROXD1 ont été récemment décrites chez des patients présentant un tableau de myopathie congénitale ou de dystrophie musculaire des ceintures [1-4]. PYROXD1 (PYRidine nucleotide-disulfide OXidoreductase Domain-containing protein 1) est une protéine exprimée de manière ubiquitaire que l’on retrouve dans le cytosol et les noyaux des fibres musculaires squelettiques. La fonction précise de PYROXD1 est peu connue et des analyses de complémentation dans la levure suggèrent qu’il s’agit d’une oxido-réductase capable de prévenir les effets du stress oxydatif [3]. La diminution de l’expression de PYROXD1 est létale lors du développement chez la drosophile, et elle altère la prolifération, la migration, et la différentiation des myoblastes murins. Cet article vise à résumer brièvement les caractéristiques cliniques, histologiques, et génétiques de la myopathie liée à PYROXD1 afin d’éclairer le mécanisme pathophysiologique de la maladie et d’analyser la corrélation entre génotype et phénotype.

Sign in / Sign up

Export Citation Format

Share Document