1
|
Baker JT, Duarte ME, Holanda DM, Kim SW. Friend or Foe? Impacts of Dietary Xylans, Xylooligosaccharides, and Xylanases on Intestinal Health and Growth Performance of Monogastric Animals. Animals (Basel) 2021; 11:609. [PMID: 33652614 PMCID: PMC7996850 DOI: 10.3390/ani11030609] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/11/2021] [Accepted: 02/24/2021] [Indexed: 12/27/2022] Open
Abstract
This paper discusses the structural difference and role of xylan, procedures involved in the production of xylooligosaccharides (XOS), and their implementation into animal feeds. Xylan is non-starch polysaccharides that share a β-(1-4)-linked xylopyranose backbone as a common feature. Due to the myriad of residues that can be substituted on the polymers within the xylan family, more anti-nutritional factors are associated with certain types of xylan than others. XOS are sugar oligomers extracted from xylan-containing lignocellulosic materials, such as crop residues, wood, and herbaceous biomass, that possess prebiotic effects. XOS can also be produced in the intestine of monogastric animals to some extent when exogenous enzymes, such as xylanase, are added to the feed. Xylanase supplementation is a common practice within both swine and poultry production to reduce intestinal viscosity and improve digestive utilization of nutrients. The efficacy of xylanase supplementation varies widely due a number of factors, one of which being the presence of xylanase inhibitors present in common feedstuffs. The use of prebiotics in animal feeding is gaining popularity as producers look to accelerate growth rate, enhance intestinal health, and improve other production parameters in an attempt to provide a safe and sustainable food product. Available research on the impact of xylan, XOS, as well as xylanase on the growth and health of swine and poultry, is also summarized. The response to xylanase supplementation in swine and poultry feeds is highly variable and whether the benefits are a result of nutrient release from NSP, reduction in digesta viscosity, production of short chain xylooligosaccharides or a combination of these is still in question. XOS supplementation seems to benefit both swine and poultry at various stages of production, as well as varying levels of XOS purity and degree of polymerization; however, further research is needed to elucidate the ideal dosage, purity, and degree of polymerization needed to confer benefits on intestinal health and performance in each respective species.
Collapse
Affiliation(s)
| | | | | | - Sung Woo Kim
- Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA; (J.T.B.); (M.E.D.); (D.M.H.)
| |
Collapse
|
2
|
Shivudu G, Khan S, Chandraraj K, Selvam P. Immobilization of Recombinant Endo‐1,4‐β‐xylanase on Ordered Mesoporous Matrices for Xylooligosaccharides Production. ChemistrySelect 2019. [DOI: 10.1002/slct.201901593] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Godhulayyagari Shivudu
- National Centre for Catalysis Research and Department of BiotechnologyIndian Institute of Technology-Madras Chennai- 600036 India
| | - Sourav Khan
- National Centre for Catalysis Research and Department of ChemistryIndian Institute of Technology-Madras Chennai- 600036 India
| | - Krishnan Chandraraj
- National Centre for Catalysis Research and Department of BiotechnologyIndian Institute of Technology-Madras Chennai- 600036 India
| | - Parasuraman Selvam
- National Centre for Catalysis Research and Department of ChemistryIndian Institute of Technology-Madras Chennai- 600036 India
- School of Chemical Engineering and Analytical ScienceThe University of Manchester, Manchester M13 9PL United Kingdom
- Department of Chemical and Process EngineeringUniversity of Surrey, Guildford, Surrey GU2 7XH United Kingdom
| |
Collapse
|
3
|
Katsimpouras C, Dedes G, Thomaidis NS, Topakas E. A novel fungal GH30 xylanase with xylobiohydrolase auxiliary activity. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:120. [PMID: 31110561 PMCID: PMC6511221 DOI: 10.1186/s13068-019-1455-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/29/2019] [Indexed: 05/09/2023]
Abstract
BACKGROUND The main representatives of hemicellulose are xylans, usually decorated β-1,4-linked d-xylose polymers, which are hydrolyzed by xylanases. The efficient utilization and complete hydrolysis of xylans necessitate the understanding of the mode of action of xylan degrading enzymes. The glycoside hydrolase family 30 (GH30) xylanases comprise a less studied group of such enzymes, and differences regarding the substrate recognition have been reported between fungal and bacterial GH30 xylanases. Besides their role in the utilization of lignocellulosic biomass for bioenergy, such enzymes could be used for the tailored production of prebiotic xylooligosaccharides (XOS) due to their substrate specificity. RESULTS The expression of a putative GH30_7 xylanase from the fungus Thermothelomyces thermophila (synonyms Myceliophthora thermophila, Sporotrichum thermophile) in Pichia pastoris resulted in the production and isolation of a novel xylanase with unique catalytic properties. The novel enzyme designated TtXyn30A, exhibited an endo- mode of action similar to that of bacterial GH30 xylanases that require 4-O-methyl-d-glucuronic acid (MeGlcA) decorations, in contrast to most characterized fungal ones. However, TtXyn30A also exhibited an exo-acting catalytic behavior by releasing the disaccharide xylobiose from the non-reducing end of XOS. The hydrolysis products from beechwood glucuronoxylan were MeGlcA substituted XOS, and xylobiose. The major uronic XOS (UXOS) were the aldotriuronic and aldotetrauronic acid after longer incubation indicating the ability of TtXyn30A to cleave linear parts of xylan and UXOS as well. CONCLUSIONS Hereby, we reported the heterologous production and biochemical characterization of a novel fungal GH30 xylanase exhibiting endo- and exo-xylanase activity. To date, considering its novel catalytic properties, TtXyn30A shows differences with most characterized fungal and bacterial GH30 xylanases. The discovered xylobiohydrolase mode of action offers new insights into fungal enzymatic systems that are employed for the utilization of lignocellulosic biomass. The recombinant xylanase could be used for the production of X2 and UXOS from glucuronoxylan, which in turn would be utilized as prebiotics carrying manifold health benefits.
Collapse
Affiliation(s)
- Constantinos Katsimpouras
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
| | - Grigorios Dedes
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
| | - Nikolaos S. Thomaidis
- Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 15771 Athens, Greece
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
- Biochemical and Chemical Process Engineering, Division of Sustainable Process Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187 Luleå, Sweden
| |
Collapse
|
4
|
Linares-Pastén JA, Aronsson A, Karlsson EN. Structural Considerations on the Use of Endo-Xylanases for the Production of prebiotic Xylooligosaccharides from Biomass. Curr Protein Pept Sci 2018; 19:48-67. [PMID: 27670134 PMCID: PMC5738707 DOI: 10.2174/1389203717666160923155209] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 08/31/2016] [Accepted: 09/15/2016] [Indexed: 11/24/2022]
Abstract
Xylooligosaccharides (XOS) have gained increased interest as prebiotics during the last years. XOS and arabinoxylooligosaccharides (AXOS) can be produced from major fractions of biomass including agricultural by-products and other low cost raw materials. Endo-xylanases are key enzymes for the production of (A)XOS from xylan. As the xylan structure is broadly diverse due to different substitutions, diverse endo-xylanases have evolved for its degradation. In this review structural and functional aspects are discussed, focusing on the potential applications of endo-xylanases in the production of differently substituted (A)XOS as emerging prebiotics, as well as their implication in the processing of the raw materials. Endo-xylanases are found in at least eight different glycoside hydrolase families (GH), and can either have a retaining or an inverting catalytic mechanism. To date, it is mainly retaining endo-xylanases that are used in applications to produce (A)XOS. Enzymes from these GH-families (mainly GH10 and GH11, and the more recently investigated GH30) are taken as prototypes to discuss substrate preferences and main products obtained. Finally, the need of new and accessory enzymes (new specificities from new families or sources) to increase the yield of different types of (A)XOS is discussed, along with in vitro tests of produced oligosaccharides and production of enzymes in GRAS organisms to facilitate use in functional food manufacturing.
Collapse
Affiliation(s)
| | - Anna Aronsson
- Biotechnology, Department of Chemistry, Lund University, Lund, Sweden
| | | |
Collapse
|
5
|
Freire F, Verma A, Bule P, Alves VD, Fontes CMGA, Goyal A, Najmudin S. Conservation in the mechanism of glucuronoxylan hydrolysis revealed by the structure of glucuronoxylan xylanohydrolase (CtXyn30A) from Clostridium thermocellum. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2016; 72:1162-1173. [PMID: 27841749 DOI: 10.1107/s2059798316014376] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/09/2016] [Indexed: 11/10/2022]
Abstract
Glucuronoxylan endo-β-1,4-xylanases cleave the xylan chain specifically at sites containing 4-O-methylglucuronic acid substitutions. These enzymes have recently received considerable attention owing to their importance in the cooperative hydrolysis of heteropolysaccharides. However, little is known about the hydrolysis of glucuronoxylans in extreme environments. Here, the structure of a thermostable family 30 glucuronoxylan endo-β-1,4-xylanase (CtXyn30A) from Clostridium thermocellum is reported. CtXyn30A is part of the cellulosome, a highly elaborate multi-enzyme complex secreted by the bacterium to efficiently deconstruct plant cell-wall carbohydrates. CtXyn30A preferably hydrolyses glucuronoxylans and displays maximum activity at pH 6.0 and 70°C. The structure of CtXyn30A displays a (β/α)8 TIM-barrel core with a side-associated β-sheet domain. Structural analysis of the CtXyn30A mutant E225A, solved in the presence of xylotetraose, revealed xylotetraose-cleavage oligosaccharides partially occupying subsites -3 to +2. The sugar ring at the +1 subsite is held in place by hydrophobic stacking interactions between Tyr139 and Tyr200 and hydrogen bonds to the OH group of Tyr227. Although family 30 glycoside hydrolases are retaining enzymes, the xylopyranosyl ring at the -1 subsite of CtXyn30A-E225A appears in the α-anomeric configuration. A set of residues were found to be strictly conserved in glucuronoxylan endo-β-1,4-xylanases and constitute the molecular determinants of the restricted specificity displayed by these enzymes. CtXyn30A is the first thermostable glucuronoxylan endo-β-1,4-xylanase described to date. This work reveals that substrate recognition by both thermophilic and mesophilic glucuronoxylan endo-β-1,4-xylanases is modulated by a conserved set of residues.
Collapse
Affiliation(s)
- Filipe Freire
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Anil Verma
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781 039, India
| | - Pedro Bule
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Victor D Alves
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Carlos M G A Fontes
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Arun Goyal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781 039, India
| | - Shabir Najmudin
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| |
Collapse
|
6
|
A novel member of family 30 glycoside hydrolase subfamily 8 glucuronoxylan endo-β-1,4-xylanase (CtXynGH30) from Clostridium thermocellum orchestrates catalysis on arabinose decorated xylans. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcatb.2016.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
7
|
Classification, mode of action and production strategy of xylanase and its application for biofuel production from water hyacinth. Int J Biol Macromol 2016; 82:1041-54. [DOI: 10.1016/j.ijbiomac.2015.10.086] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 10/26/2015] [Accepted: 10/27/2015] [Indexed: 01/07/2023]
|
8
|
St John FJ, Dietrich D, Crooks C, Pozharski E, González JM, Bales E, Smith K, Hurlbert JC. A novel member of glycoside hydrolase family 30 subfamily 8 with altered substrate specificity. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:2950-8. [PMID: 25372685 PMCID: PMC4722856 DOI: 10.1107/s1399004714019531] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 08/28/2014] [Indexed: 11/10/2022]
Abstract
Endoxylanases classified into glycoside hydrolase family 30 subfamily 8 (GH30-8) are known to hydrolyze the hemicellulosic polysaccharide glucuronoxylan (GX) but not arabinoxylan or neutral xylooligosaccharides. This is owing to the specificity of these enzymes for the α-1,2-linked glucuronate (GA) appendage of GX. Limit hydrolysis of this substrate produces a series of aldouronates each containing a single GA substituted on the xylose penultimate to the reducing terminus. In this work, the structural and biochemical characterization of xylanase 30A from Clostridium papyrosolvens (CpXyn30A) is presented. This xylanase possesses a high degree of amino-acid identity to the canonical GH30-8 enzymes, but lacks the hallmark β8-α8 loop region which in part defines the function of this GH30 subfamily and its role in GA recognition. CpXyn30A is shown to have a similarly low activity on all xylan substrates, while hydrolysis of xylohexaose revealed a competing transglycosylation reaction. These findings are directly compared with the model GH30-8 enzyme from Bacillus subtilis, XynC. Despite its high sequence identity to the GH30-8 enzymes, CpXyn30A does not have any apparent specificity for the GA appendage. These findings confirm that the typically conserved β8-α8 loop region of these enzymes influences xylan substrate specificity but not necessarily β-1,4-xylanase function.
Collapse
Affiliation(s)
- Franz J. St John
- Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA
| | - Diane Dietrich
- Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA
| | - Casey Crooks
- Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA
| | - Edwin Pozharski
- Department of Biochemistry and Molecular Biology, University of Maryland, Maryland, USA
| | - Javier M. González
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Elizabeth Bales
- Department of Chemistry, Physics and Geology, Winthrop University, Rock Hill, South Carolina, USA
| | - Kennon Smith
- Department of Chemistry, Physics and Geology, Winthrop University, Rock Hill, South Carolina, USA
| | - Jason C. Hurlbert
- Department of Chemistry, Physics and Geology, Winthrop University, Rock Hill, South Carolina, USA
| |
Collapse
|
9
|
Sainz-Polo MÁ, Valenzuela SV, Pastor FJ, Sanz-Aparicio J. Crystallization and preliminary X-ray diffraction analysis of Xyn30D from Paenibacillus barcinonensis. Acta Crystallogr F Struct Biol Commun 2014; 70:963-6. [PMID: 25005099 PMCID: PMC4089542 DOI: 10.1107/s2053230x14012035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 05/23/2014] [Indexed: 11/10/2022] Open
Abstract
Xyn30D, a new member of a recently identified group of xylanases, has been purified and crystallized. Xyn30D is a bimodular enzyme composed of an N-terminal catalytic domain belonging to glycoside hydrolase family 30 (GH30) and a C-terminal family 35 carbohydrate-binding domain (CBM35) able to bind xylans and glucuronic acid. Xyn30D shares the characteristic endo mode of action described for GH30 xylanases, with the hydrolysis of the β-(1,4) bonds of xylan being directed by α-1,2-linked glucuronate moieties, which have to be placed at the -2 subsite of the xylanase active site. Crystals of the complete enzyme were obtained and a full data set to 2.3 Å resolution was collected using a synchrotron X-ray source. This represents the first bimodular enzyme with the domain architecture GH30-CBM35. This study will contribute to the understanding of the role that the different xylanases play in the depolymerization of glucuronoxylan.
Collapse
Affiliation(s)
- María Ángela Sainz-Polo
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry ‘Rocasolano’, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain
| | - Susana Valeria Valenzuela
- Department of Microbiology, Faculty of Biology, Universitat de Barcelona, Avenida Diagonal 643, 08028 Barcelona, Spain
| | - F. Javier Pastor
- Department of Microbiology, Faculty of Biology, Universitat de Barcelona, Avenida Diagonal 643, 08028 Barcelona, Spain
| | - Julia Sanz-Aparicio
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry ‘Rocasolano’, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain
| |
Collapse
|
10
|
Verma AK, Goyal A. In silico structural characterization and molecular docking studies of first glucuronoxylan-xylanohydrolase (Xyn30A) from family 30 glycosyl hydrolase (GH30) from Clostridium thermocellum. Mol Biol 2014. [DOI: 10.1134/s0026893314020022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
11
|
Verma AK, Goyal A, Freire F, Bule P, Venditto I, Brás JLA, Santos H, Cardoso V, Bonifácio C, Thompson A, Romão MJ, Prates JAM, Ferreira LMA, Fontes CMGA, Najmudin S. Overexpression, crystallization and preliminary X-ray crystallographic analysis of glucuronoxylan xylanohydrolase (Xyn30A) from Clostridium thermocellum. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1440-2. [PMID: 24316849 PMCID: PMC3855739 DOI: 10.1107/s1744309113025050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 09/09/2013] [Indexed: 11/10/2022]
Abstract
The modular carbohydrate-active enzyme belonging to glycoside hydrolase family 30 (GH30) from Clostridium thermocellum (CtXynGH30) is a cellulosomal protein which plays an important role in plant cell-wall degradation. The full-length CtXynGH30 contains an N-terminal catalytic module (Xyn30A) followed by a family 6 carbohydrate-binding module (CBM6) and a dockerin at the C-terminus. The recombinant protein has a molecular mass of 45 kDa. Preliminary structural characterization was carried out on Xyn30A crystallized in different conditions. All tested crystals belonged to space group P1 with one molecule in the asymmetric unit. Molecular replacement has been used to solve the Xyn30A structure.
Collapse
Affiliation(s)
- Anil Kumar Verma
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781 039, India
| | - Arun Goyal
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781 039, India
| | - Filipe Freire
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Pedro Bule
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Immacolata Venditto
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Joana L. A. Brás
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Helena Santos
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Vânia Cardoso
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Cecília Bonifácio
- REQUIMTE–CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Andrew Thompson
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, 91192 Gif-sur-Yvette, France
| | - Maria João Romão
- REQUIMTE–CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - José A. M. Prates
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Luís M. A. Ferreira
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Carlos M. G. A. Fontes
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Shabir Najmudin
- CIISA–Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| |
Collapse
|
12
|
St John FJ, Hurlbert JC, Rice JD, Preston JF, Pozharski E. Ligand bound structures of a glycosyl hydrolase family 30 glucuronoxylan xylanohydrolase. J Mol Biol 2011; 407:92-109. [PMID: 21256135 DOI: 10.1016/j.jmb.2011.01.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 01/04/2011] [Accepted: 01/05/2011] [Indexed: 10/18/2022]
Abstract
Xylanases of glycosyl hydrolase family 30 (GH30) have been shown to cleave β-1,4 linkages of 4-O-methylglucuronoxylan (MeGX(n)) as directed by the position along the xylan chain of an α-1,2-linked 4-O-methylglucuronate (MeGA) moiety. Complete hydrolysis of MeGX(n) by these enzymes results in singly substituted aldouronates having a 4-O-methylglucuronate moiety linked to a xylose penultimate from the reducing terminal xylose and some number of xylose residues toward the nonreducing terminus. This novel mode of action distinguishes GH30 xylanases from the more common xylanase families that cleave MeGX(n) in accessible regions. To help understand this unique biochemical function, we have determined the structure of XynC in its native and ligand-bound forms. XynC structure models derived from diffraction data of XynC crystal soaks with the simple sugar glucuronate (GA) and the tetrameric sugar 4-O-methyl-aldotetrauronate resulted in models containing GA and 4-O-methyl-aldotriuronate, respectively. Each is observed in two locations within XynC surface openings. Ligand coordination occurs within the XynC catalytic substrate binding cleft and on the structurally fused side β-domain, demonstrating a substrate targeting role for this putative carbohydrate binding module. Structural data reveal that GA acts as a primary functional appendage for recognition and hydrolysis of the MeGX(n) polymer by the protein. This work compares the structure of XynC with a previously reported homologous enzyme, XynA, from Erwinia chrysanthemi and analyzes the ligand binding sites. Our results identify the molecular interactions that define the unique function of XynC and homologous GH30 enzymes.
Collapse
Affiliation(s)
- Franz J St John
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA.
| | | | | | | | | |
Collapse
|
13
|
St John FJ, González JM, Pozharski E. Consolidation of glycosyl hydrolase family 30: a dual domain 4/7 hydrolase family consisting of two structurally distinct groups. FEBS Lett 2010; 584:4435-41. [PMID: 20932833 DOI: 10.1016/j.febslet.2010.09.051] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 09/23/2010] [Accepted: 09/30/2010] [Indexed: 12/26/2022]
Abstract
In this work glycosyl hydrolase (GH) family 30 (GH30) is analyzed and shown to consist of its currently classified member sequences as well as several homologous sequence groups currently assigned within family GH5. A large scale amino acid sequence alignment and a phylogenetic tree were generated and GH30 groups and subgroups were designated. A partial rearrangement in the GH30 defining side-associated β-domain contributes to the differentiation of two major groups that contain up to eight subgroups. For this CAZy family of Clan A enzymes the dual domain fold is conserved, suggesting that it may be a requirement for evolved function. This work redefines GH family 30 and serves as a guide for future efforts regarding enzymes classified within this family.
Collapse
Affiliation(s)
- Franz J St John
- University of Maryland, School of Pharmacy, Department of Pharmaceutical Sciences, Baltimore, MD, USA
| | | | | |
Collapse
|
14
|
Gilbert HJ. The biochemistry and structural biology of plant cell wall deconstruction. PLANT PHYSIOLOGY 2010; 153:444-55. [PMID: 20406913 PMCID: PMC2879781 DOI: 10.1104/pp.110.156646] [Citation(s) in RCA: 217] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 04/17/2010] [Indexed: 05/18/2023]
Affiliation(s)
- Harry J Gilbert
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA.
| |
Collapse
|
15
|
Pollet A, Delcour JA, Courtin CM. Structural determinants of the substrate specificities of xylanases from different glycoside hydrolase families. Crit Rev Biotechnol 2010; 30:176-91. [DOI: 10.3109/07388551003645599] [Citation(s) in RCA: 176] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|