Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Analysis of nasturtium TmNXG1 complexes by crystallography and molecular dynamics provides detailed insight into substrate recognition by family GH16 xyloglucan endo-transglycosylases and endo-hydrolases
KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
Visa övriga samt affilieringar
2009 (Engelska)Ingår i: Proteins: Structure, Function, and Bioinformatics, ISSN 0887-3585, E-ISSN 1097-0134, Vol. 75, nr 4, s. 820-836Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Reorganization and degradation of the wall crosslinking and seed storage polysaccharide xyloglucan by glycoside hydrolase family 16 (GH16) endo-transglycosylases and hydrolases are crucial to the growth of the majority of land plants, affecting processes as diverse as germination, morphogenesis, and fruit ripening. A high-resolution, three-dimensional structure of a nasturtium (Tropaeolum majus) endo-xyloglucanase loop mutant, TmNXG1-Delta YNIIG, with an ohgosaccharide product bound in the negative active-site subsites, has been solved by X-ray crystallography. Comparison of this novel complex to that of the strict xyloglucan endotransglycosylase PttXET16-34 from hybrid aspen (Populus tremula x tremuloides), previously solved with a xylogluco-oligosaccharide bound in the positive subsites, highlighted key protein structures that affect the disparate catalytic activities displayed by these closely related enzymes. Combination of these "partial" active-site complexes through molecular dynamics simulations in water allowed modeling of wild-type TmNXG1, TmNXG1-Delta YNIIG, and wild-type PttXET16-34 in complex with a xyloglucan octadecasaccharide spanning the entire catalytic cleft. A comprehensive analysis of these full-length complexes underscored the importance of various loops lining the active site. Subtle differences leading to a tighter hydrogen bonding pattern on the negative (glycosyl donor) binding subsites, together with loop flexibility on the positive (glycosyl acceptor) binding subsites appear to favor hydrolysis over transglycosylation in GH16 xyloglucan-active enzymes.

Ort, förlag, år, upplaga, sidor
2009. Vol. 75, nr 4, s. 820-836
Nyckelord [en]
xyloglucan, nasturtium seedlings, cell wall polysaccharides, crystal, structure, molecular dynamics, cell-walls, glycoside hydrolases, crystal-structures, oligosaccharides, endotransglycosylase, nomenclature, acceptor, perspectives, degradation, cotyledons
Identifikatorer
URN: urn:nbn:se:kth:diva-18433DOI: 10.1002/prot.22291ISI: 000266133600004Scopus ID: 2-s2.0-66149174788OAI: oai:DiVA.org:kth-18433DiVA, id: diva2:336480
Anmärkning

QC 20100902

Tillgänglig från: 2010-08-05 Skapad: 2010-08-05 Senast uppdaterad: 2018-01-26Bibliografiskt granskad
Ingår i avhandling
1. On the engineering of proteins: methods and applications for carbohydrate-active enzymes
Öppna denna publikation i ny flik eller fönster >>On the engineering of proteins: methods and applications for carbohydrate-active enzymes
2010 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

This thesis presents the application of different protein engineering methods on enzymes and non-catalytic proteins that act upon xyloglucans. Xyloglucans are polysaccharides found as storage polymers in seeds and tubers, and as cross-linking glucans in the cell wall of plants. Their structure is complex with intricate branching patterns, which contribute to the physical properties of the polysaccharide including its binding to and interaction with other glucans such as cellulose.

One important group of xyloglucan-active enzymes is encoded by the GH16 XTH gene family in plants, including xyloglucan endo-transglycosylases (XET) and xyloglucan endo-hydrolases (XEH). The molecular determinants behind the different catalytic routes of these homologous enzymes are still not fully understood. By combining structural data and molecular dynamics (MD) simulations, interesting facts were revealed about enzyme-substrate interaction. Furthermore, a pilot study was performed using structure-guided recombination to generate a restricted library of XET/XEH chimeras.

Glycosynthases are hydrolytically inactive mutant glycoside hydrolases (GH) that catalyse the formation of glycosidic linkages between glycosyl fluoride donors and glycoside acceptors. Different enzymes with xyloglucan hydrolase activity were engineered into glycosynthases, and characterised as tools for the synthesis of well-defined homogenous xyloglucan oligo- and polysaccharides with regular substitution patterns.

Carbohydrate-binding modules (CBM) are non-catalytic protein domains that bind to polysaccharidic substrates. An important technical application involves their use as molecular probes to detect and localise specific carbohydrates in vivo. The three-dimensional structure of an evolved xyloglucan binding module (XGBM) was solved by X-ray diffraction. Affinity-guided directed evolution of this first generation XGBM resulted in highly specific probes that were used to localise non-fucosylated xyloglucans in plant tissue sections.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH, 2010. s. xii, 74
Serie
Trita-BIO-Report, ISSN 1654-2312 ; 2010:14
Nyckelord
enzyme engineering, rational design, directed evolution, DNA shuffling, glycosynthase, xyloglucan, xyloglucan endo-transglycosylase, retaining glycoside hydrolase, xyloglucanase, carbohydrate binding module, polysaccharide synthesis
Nationell ämneskategori
Industriell bioteknik
Identifikatorer
urn:nbn:se:kth:diva-24296 (URN)978-91-7415-709-3 (ISBN)
Disputation
2010-09-22, FD5, AlbaNova Universitetscentrum, Roslagstullsbacken 21, Stockholm, 10:15 (Engelska)
Opponent
Handledare
Anmärkning
QC 20100902Tillgänglig från: 2010-09-02 Skapad: 2010-08-31 Senast uppdaterad: 2010-09-02Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextScopus

Sök vidare i DiVA

Av författaren/redaktören
Mark, PekkaBaumann, Martin J.Eklöf, Jens M.Gullfot, FredrikaKallas, Åsa M.Teeri, Tuula T.Brumer, Harry
Av organisationen
Glykovetenskap
I samma tidskrift
Proteins: Structure, Function, and Bioinformatics

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 94 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf