Dynamics of starch granule biogenesis – the role of redox-regulated enzymes and low-affinity carbohydrate-binding modules

AbstractFibronectin type III (FNIII) domains were first identified in the eukaryotic plasma protein fibronectin, where they act as structural spacers or enable protein-protein interactions. Recently we characterized two large and multi-domain amylases in Microbacterium aurum B8.A that both carry multiple FNIII and carbohydrate binding modules (CBMs). The role of (multiple) FNIII domains in such carbohydrate acting enzymes is currently unclear. Four hypothetical functions are considered here: a substrate surface disruption domain, a carbohydrate binding module, as a stable linker, or enabling protein-protein interactions. We performed a phylogenetic analysis of all FNIII domains identified in proteins listed in the CAZy database. These data clearly show that the FNIII domains in eukaryotic and archaeal CAZy proteins are of bacterial origin and also provides examples of interkingdom gene transfer from Bacteria to Archaea and Eucarya. FNIII domains occur in a wide variety of CAZy enzymes acting on many different substrates, suggesting that they have a non-specific role in these proteins. While CBM domains are mostly found at protein termini, FNIII domains are commonly located between other protein domains. FNIII domains in carbohydrate acting enzymes thus may function mainly as stable linkers to allow optimal positioning and/or flexibility of the catalytic domain and other domains, such as CBM.

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Reassembly and co-crystallization of a family 9 processive endoglucanase from its component parts: Structural and functional significance of the intermodular linker

10.7287/peerj.preprints.1133 ◽

2015 ◽

Author(s):

Svetlana Petkun ◽

Inna Rozman Grinberg ◽

Raphael Lamed ◽

Sadanari Jindou ◽

Tal Burstein ◽

...

Keyword(s):

Glycoside Hydrolase ◽

Spatial Organization ◽

Cellulase Activity ◽

Titration Calorimetry ◽

Carbohydrate Binding ◽

Endoglucanase Activity ◽

Carbohydrate Binding Modules ◽

Processive Endoglucanase ◽

Catalytic Module

Non-cellulosomal processive endoglucanase 9I (Cel9I) from Clostridium thermocellum is a modular protein, consisting of a family-9 glycoside hydrolase (GH9) catalytic module and two family-3 carbohydrate-binding modules (CBM3c and CBM3b), separated by linker regions. GH9 does not show cellulase activity when expressed without CBM3c and CBM3b and the presence of the CBM3c was previously shown to be essential for endoglucanase activity. Physical reassociation of independently expressed GH9 and CBM3c modules (containing linker sequences) restored 60-70% of the intact Cel9I endocellulase activity. However, the mechanism responsible for recovery of activity remained unclear. In this work we independently expressed recombinant GH9 and CBM3c with and without their interconnecting linker in Escherichia coli. We crystallized and determined the molecular structure of the GH9/linker-CBM3c heterodimer at a resolution of 1.68 Å to understand the functional and structural importance of the mutual spatial orientation of the modules and the role of the interconnecting linker during their re-association. Enzyme activity assays and isothermal titration calorimetry were performed to study and compare the effect of the linker on the re-association. The results indicated that reassembly of the modules could also occur without the linker, albeit with only very low recovery of endoglucanase activity. We propose that the linker regions in the GH9/CBM3c endoglucanases are important for spatial organization and fixation of the modules into functional enzymes.

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Reassembly and co-crystallization of a family 9 processive endoglucanase from its component parts: Structural and functional significance of the intermodular linker

10.7287/peerj.preprints.1133v1 ◽

2015 ◽

Author(s):

Svetlana Petkun ◽

Inna Rozman Grinberg ◽

Raphael Lamed ◽

Sadanari Jindou ◽

Tal Burstein ◽

...

Keyword(s):

Glycoside Hydrolase ◽

Spatial Organization ◽

Cellulase Activity ◽

Titration Calorimetry ◽

Carbohydrate Binding ◽

Endoglucanase Activity ◽

Carbohydrate Binding Modules ◽

Processive Endoglucanase ◽

Catalytic Module

Non-cellulosomal processive endoglucanase 9I (Cel9I) from Clostridium thermocellum is a modular protein, consisting of a family-9 glycoside hydrolase (GH9) catalytic module and two family-3 carbohydrate-binding modules (CBM3c and CBM3b), separated by linker regions. GH9 does not show cellulase activity when expressed without CBM3c and CBM3b and the presence of the CBM3c was previously shown to be essential for endoglucanase activity. Physical reassociation of independently expressed GH9 and CBM3c modules (containing linker sequences) restored 60-70% of the intact Cel9I endocellulase activity. However, the mechanism responsible for recovery of activity remained unclear. In this work we independently expressed recombinant GH9 and CBM3c with and without their interconnecting linker in Escherichia coli. We crystallized and determined the molecular structure of the GH9/linker-CBM3c heterodimer at a resolution of 1.68 Å to understand the functional and structural importance of the mutual spatial orientation of the modules and the role of the interconnecting linker during their re-association. Enzyme activity assays and isothermal titration calorimetry were performed to study and compare the effect of the linker on the re-association. The results indicated that reassembly of the modules could also occur without the linker, albeit with only very low recovery of endoglucanase activity. We propose that the linker regions in the GH9/CBM3c endoglucanases are important for spatial organization and fixation of the modules into functional enzymes.

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Functional diversity of three tandem C-terminal carbohydrate-binding modules of a β-mannanase

Journal of Biological Chemistry ◽

10.1016/j.jbc.2021.100638 ◽

2021 ◽

pp. 100638

Author(s):

Marie Sofie Møller ◽

Souad El Bouaballati ◽

Bernard Henrissat ◽

Birte Svensson

Keyword(s):

Functional Diversity ◽

Carbohydrate Binding ◽

Carbohydrate Binding Modules

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Functionalization of Cellulose-Based Hydrogels with Bi-Functional Fusion Proteins Containing Carbohydrate-Binding Modules

Materials ◽

10.3390/ma14123175 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3175

Author(s):

Mariana Barbosa ◽

Hélvio Simões ◽

Duarte Miguel F. Prazeres

Keyword(s):

Fusion Proteins ◽

Fluorescent Protein ◽

Protein A ◽

Chemical Properties ◽

Main Idea ◽

Bioactive Molecules ◽

Scaffolding Protein ◽

Carbohydrate Binding ◽

Biological Interactions ◽

Carbohydrate Binding Modules

Materials with novel and enhanced functionalities can be obtained by modifying cellulose with a range of biomolecules. This functionalization can deliver tailored cellulose-based materials with enhanced physical and chemical properties and control of biological interactions that match specific applications. One of the foundations for the success of such biomaterials is to efficiently control the capacity to combine relevant biomolecules into cellulose materials in such a way that the desired functionality is attained. In this context, our main goal was to develop bi-functional biomolecular constructs for the precise modification of cellulose hydrogels with bioactive molecules of interest. The main idea was to use biomolecular engineering techniques to generate and purify different recombinant fusions of carbohydrate binding modules (CBMs) with significant biological entities. Specifically, CBM-based fusions were designed to enable the bridging of proteins or oligonucleotides with cellulose hydrogels. The work focused on constructs that combine a family 3 CBM derived from the cellulosomal-scaffolding protein A from Clostridium thermocellum (CBM3) with the following: (i) an N-terminal green fluorescent protein (GFP) domain (GFP-CBM3); (ii) a double Z domain that recognizes IgG antibodies; and (iii) a C-terminal cysteine (CBM3C). The ability of the CBM fusions to bind and/or anchor their counterparts onto the surface of cellulose hydrogels was evaluated with pull-down assays. Capture of GFP-CBM3 by cellulose was first demonstrated qualitatively by fluorescence microscopy. The binding of the fusion proteins, the capture of antibodies (by ZZ-CBM3), and the grafting of an oligonucleotide (to CBM3C) were successfully demonstrated. The bioactive cellulose platform described here enables the precise anchoring of different biomolecules onto cellulose hydrogels and could contribute significatively to the development of advanced medical diagnostic sensors or specialized biomaterials, among others.

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Integrated Counts of Carbohydrate-Active Protein Domains as Metabolic Readouts to Distinguish Probiotic Biology and Human Fecal Metagenomes

Scientific Reports ◽

10.1038/s41598-019-53173-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Hong-Hsing Liu ◽

Yu-Chen Lin ◽

Chen-Shuan Chung ◽

Kevin Liu ◽

Ya-Hui Chang ◽

...

Keyword(s):

Markov Models ◽

Protein Domains ◽

Degradation Pathway ◽

The Other ◽

Carbohydrate Binding ◽

Gram Stain ◽

Active Protein ◽

Metabolic Potential ◽

Independent Validation ◽

Carbohydrate Binding Modules

AbstractBowel microbiota is a “metaorgan” of metabolisms on which quantitative readouts must be performed before interventions can be introduced and evaluated. The study of the effects of probiotic Clostridium butyricum MIYAIRI 588 (CBM588) on intestine transplantees indicated an increased percentage of the “other glycan degradation” pathway in 16S-rRNA-inferred metagenomes. To verify the prediction, a scoring system of carbohydrate metabolisms derived from shotgun metagenomes was developed using hidden Markov models. A significant correlation (R = 0.9, p < 0.015) between both modalities was demonstrated. An independent validation revealed a strong complementarity (R = −0.97, p < 0.002) between the scores and the abundance of “glycogen degradation” in bacteria communities. On applying the system to bacteria genomes, CBM588 had only 1 match and ranked higher than the other 8 bacteria evaluated. The gram-stain properties were significantly correlated to the scores (p < 5 × 10−4). The distributions of the scored protein domains indicated that CBM588 had a considerably higher (p < 10−5) proportion of carbohydrate-binding modules than other bacteria, which suggested the superior ability of CBM588 to access carbohydrates as a metabolic driver to the bowel microbiome. These results demonstrated the use of integrated counts of protein domains as a feasible readout for metabolic potential within bacteria genomes and human metagenomes.

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