Home About Browse Search
Svenska


High resolution crystal structure of the Endo-N-acetyl-beta-D-glucosaminidase responsible for the deglycosylation of hypocrea jecorina cellulases

Sandgren, Mats and Karkehabadi, Saeid (2012). High resolution crystal structure of the Endo-N-acetyl-beta-D-glucosaminidase responsible for the deglycosylation of hypocrea jecorina cellulases. PloS one. 7:7, 1-13
[Journal article]

[img]
Preview
PDF
2MB

Official URL: http://dx.doi.org/10.1371/journal.pone.0040854

Abstract

Endo-N-acetyl-beta-D-glucosaminidases (ENGases) hydrolyze the glycosidic linkage between the two N-acetylglucosamine units that make up the chitobiose core of N-glycans. The endo-N-acetyl-beta-D-glucosaminidases classified into glycoside hydrolase family 18 are small, bacterial proteins with different substrate specificities. Recently two eukaryotic family 18 deglycosylating enzymes have been identified. Here, the expression, purification and the 1.3 angstrom resolution structure of the ENGase ( Endo T) from the mesophilic fungus Hypocrea jecorina (anamorph Trichoderma reesei) are reported. Although the mature protein is C-terminally processed with removal of a 46 amino acid peptide, the protein has a complete (beta/alpha) 8 TIM-barrel topology. In the active site, the proton donor (E131) and the residue stabilizing the transition state (D129) in the substrate assisted catalysis mechanism are found in almost identical positions as in the bacterial GH18 ENGases: Endo H, Endo F1, Endo F3, and Endo BT. However, the loops defining the substrate-binding cleft vary greatly from the previously known ENGase structures, and the structures also differ in some of the alpha-helices forming the barrel. This could reflect the variation in substrate specificity between the five enzymes. This is the first three-dimensional structure of a eukaryotic endo-N-acetyl-beta-D-glucosaminidase from glycoside hydrolase family 18. A glycosylation analysis of the cellulases secreted by a Hypocrea jecorina Endo T knock-out strain shows the in vivo function of the protein. A homology search and phylogenetic analysis show that the two known enzymes and their homologues form a large but separate cluster in subgroup B of the fungal chitinases. Therefore the future use of a uniform nomenclature is proposed.

Authors/Creators:Sandgren, Mats and Karkehabadi, Saeid
Title:High resolution crystal structure of the Endo-N-acetyl-beta-D-glucosaminidase responsible for the deglycosylation of hypocrea jecorina cellulases
Series/Journal:PloS one (1932-6203)
Year of publishing :2012
Volume:7
Number:7
Page range:1-13
Number of Pages:13
Publisher:Public Library of Science
ISSN:1932-6203
Language:English
Publication Type:Journal article
Refereed:Yes
Article category:Scientific peer reviewed
Version:Published version
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) > Microbiology (Microbiology in the medical area to be 30109)
Keywords:Endo-N-acetyl- b -D-glucosaminidase, Deglycosylation, bacterial proteins, deglycosylating enzymes
URN:NBN:urn:nbn:se:slu:epsilon-e-1494
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-1494
Additional ID:
Type of IDID
Web of Science (WoS)000306950900013
DOI10.1371/journal.pone.0040854
ID Code:10330
Department:(NL, NJ) > Dept. of Molecular Biology (until 131231)
Deposited By: SLUpub Connector
Deposited On:17 Jun 2013 09:08
Metadata Last Modified:24 Jan 2015 01:50

Repository Staff Only: item control page