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GH7 cellobiohydrolases structural, functional and evolutional aspects

Borisova, Anna (2017). GH7 cellobiohydrolases structural, functional and evolutional aspects. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2017:57
ISBN 978-91-7760-004-6
eISBN 978-91-7760-005-3
[Doctoral thesis]

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Abstract

Fungal glycoside hydrolase family 7 cellobiohydrolases (GH7 CBH) are the workhorses of cellulose degradation and, thus, play a key role in the recycling of biomass on Earth. As central as these enzymes are to biomass degradation, they have become the cornerstone of modern industrial enzyme cocktails for biofuels processes.
By combination of X-ray cystallography structure studies and other approaches, this thesis provides essential impact into understanding of sequence, structure and function correlation concepts in the GH7 family.

Several new GH7 CBH structures were solved, ranging from the distant Amoebozoa to Trichoderma atroviride Cel7A, which is a close ortholog to the archetypal Trichoderma reesei Cel7A. Another ascomycete fungus, Scytalidium sp., exhibits new features of GH7 CBHs, never observed before. Namely, Scytalidium sp. Cel7A revealed O-glycosylation on the tunnel-enclosing B2 loop, and the loop can adopt different conformations, and even bend into the tunnel and obstruct cellulose binding. Trichoderma atroviride Cel7A ligand complex with thio-cellotriose represents a sliding intermediate during processive cellulose hydrolysis. Three new structures of GH7 CBHs labeled with a novel mechanism-based affinity tag confirm the proposed inactivation mechanism, presenting covalently bound enzyme-ligand complexes with Trichoderma reesei Cel7A and Scytalidium sp. Cel7A, and one complex with Trichoderma reesei Cel7A E217Q acid/base mutant where covalent bond is not formed. Two crystal structures of social amoeba GH7 CBHs appeared to be very similar to the well-studied fungal Trichoderma reesei Cel7A, despite the large evolutionary distance between these organisms. Phylogenetic analysis revealed high similarity between GH7 CBHs from different branches of the eukaryotic tree of life. Biochemical characterization and performance assays of the novel GH7 CBHs along with Molecular Dynamics (MD) simulations based on their structures, highlight important loop regions implicated in processivity, binding in the product sites, endo-/exo-initiation as well as thermostability and initiation of thermal unfolding. Reverse concervation analysis (RCA) identified potentially important evolutionary target sites in Trichoderma spp GH7 sequences. Loop dynamics and correlation with structure and function of GH7 CBH is thoroughly discussed in the thesis.

Authors/Creators:Borisova, Anna
Title:GH7 cellobiohydrolases structural, functional and evolutional aspects
Series/Journal:Acta Universitatis agriculturae Sueciae (1652-6880)
Year of publishing :May 2017
Depositing date:11 May 2017
Volume:2017:57
Number of Pages:71
Papers/manuscripts:
NumberReferences
IHobdey, S.E.; Knott, B.C.; Momeni, M.H.; Taylor, L.E.; Borisova, A.S.; Podkaminer, K.K.; VanderWall, T.A.; Himmel, M.E.; Decker, S.R.; Beckham, G.T.; Ståhlberg, J. (2016). Biochemical and structural characterization of two Dictyostelium cellobiohydrolases from the Amoebozoa kingdom reveal a high conservation between distant phylogenetic trees of life. Applied and Environmental Microbiology, 82(11):3395-409.
IIBorisova, A.S.; Eneyskaya, E.V.; Jana, S.; Badino S.F.; Kari, J.; Amore, A.; Karlsson, M.; Hansson, H.; Sandgren, M.; Himmel, M.E.; Westh, P.; Payne, C.M.; Kulminskaya, A.A.; Ståhlberg, J. Correlation of structure, function and protein dynamics in GH7 cellobiohydrolases from Trichoderma atroviride, T. reesei and T. harzianum. (Manuscript).
IIIBorisova, A.S; Eneyskaya, E.V.; Bobrov, K.S.; Jana, S.; Logachev, A.; Polev, D.E.; Lapidus, A.L.; Ibatullin, F.M.; Saleem, U.; Sandgren, M.; Payne, C.M.; Kulminskaya, A.A.; Ståhlberg, J. (2015). Sequencing, biochemical characterization, crystal structure and molecular dynamics of cellobiohydrolase Cel7A from Geotrichum candidum 3C. FEBS Journal, 282(23):4515-37.
IVBorisova, A.S.; Hansson, H.; Rasmussen, T.S.; Zierke, M.; Withers, S.G.; Ståhlberg, J. Crystal structures of mechanism-based affinity labelled GH7 cellobiohydrolases. (Manuscript).
Place of Publication:Uppsala
Publisher:Department of Molecular Sciences, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-7760-004-6
ISBN for electronic version:978-91-7760-005-3
ISSN:1652-6880
Language:English
Additional Information:author's e-mail address: <anna.borisova@slu.se>
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:X Agricola extesions > X30 Life sciences
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Structural Biology
(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Biochemistry and Molecular Biology
Agrovoc terms:cellulose, cellobiose, dictyostelium, trichoderma, scytalidium, molecular biology
Keywords:cellulose, cellobiohydrolase, X-ray structure, molecular dynamics, Trichoderma, Dictyostelium, Scytalidium
URN:NBN:urn:nbn:se:slu:epsilon-e-4171
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-4171
ID Code:14290
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Department of Molecular Sciences
Deposited By: Anna Borisova
Deposited On:18 May 2017 10:20
Metadata Last Modified:18 May 2017 10:20

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