Modeled 3D-Structures of Proteobacterial Transglycosylases from Glycoside Hydrolase Family 17 Give Insight in Ligand Interactions Explaining Differences in Transglycosylation Products
Linares-Pastén, Javier A. LU
; Jonsdottir, Lilja Björk
; Hreggvidsson, Gudmundur O.
; Fridjonsson, Olafur H.
; Watzlawick, Hildegard
and Nordberg Karlsson, Eva
LU
(2021)
In Applied Sciences (Switzerland)
11(9).
- Abstract
- The structures of glycoside hydrolase family 17 (GH17) catalytic modules from modular proteins in the ndvB loci in Pseudomonas aeruginosa (Glt1), P. putida (Glt3) and Bradyrhizobium diazoefficiens (previously B. japonicum) (Glt20) were modeled to shed light on reported differences between these homologous transglycosylases concerning substrate size, preferred cleavage site (from reducing end (Glt20: DP2 product) or non-reducing end (Glt1, Glt3: DP4 products)), branching (Glt20) and linkage formed (1,3-linkage in Glt1, Glt3 and 1,6-linkage in Glt20). Hybrid models were built and stability of the resulting TIM-barrel structures was supported by molecular dynamics simulations. Catalytic amino acids were identified... (More)
- The structures of glycoside hydrolase family 17 (GH17) catalytic modules from modular proteins in the ndvB loci in Pseudomonas aeruginosa (Glt1), P. putida (Glt3) and Bradyrhizobium diazoefficiens (previously B. japonicum) (Glt20) were modeled to shed light on reported differences between these homologous transglycosylases concerning substrate size, preferred cleavage site (from reducing end (Glt20: DP2 product) or non-reducing end (Glt1, Glt3: DP4 products)), branching (Glt20) and linkage formed (1,3-linkage in Glt1, Glt3 and 1,6-linkage in Glt20). Hybrid models were built and stability of the resulting TIM-barrel structures was supported by molecular dynamics simulations. Catalytic amino acids were identified by superimposition of GH17 structures, and function was verified by mutagenesis using Glt20 as template (i.e., E120 and E209). Ligand docking revealed six putative subsites (−4, −3, −2, −1, +1 and +2), and the conserved interacting residues suggest substrate binding in the same orientation in all three transglycosylases, despite release of the donor oligosaccharide product from either the reducing (Glt20) or non-reducing end (Glt1, Gl3). Subsites +1 and +2 are most conserved and the difference in release is likely due to changes in loop structures, leading to loss of hydrogen bonds in Glt20. Substrate docking in Glt20 indicate that presence of covalently bound donor in glycone subsites −4 to −1 creates space to accommodate acceptor oligosaccharide in alternative subsites in the catalytic cleft, promoting a branching point and formation of a 1,6-linkage. The minimum donor size of DP5, can be explained assuming preferred binding of DP4 substrates in subsite −4 to −1, preventing catalysis. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/b1efa33f-7a6a-48d4-8652-526545762b58
- author
- Linares-Pastén, Javier A.
LU
; Jonsdottir, Lilja Björk
; Hreggvidsson, Gudmundur O.
; Fridjonsson, Olafur H.
; Watzlawick, Hildegard
and Nordberg Karlsson, Eva
LU
- organization
- publishing date
- 2021-04-29
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- transglycosylation, laminarioligosaccharides, transglycosidase, 3D-structure, molecular dynamics, Bradyrhizobium, Pseudomonas
- in
- Applied Sciences (Switzerland)
- volume
- 11
- issue
- 9
- article number
- 4048
- publisher
- MDPI AG
- external identifiers
-
- scopus:85105801538
- ISSN
- 2076-3417
- DOI
- 10.3390/app11094048
- language
- English
- LU publication?
- yes
- id
- b1efa33f-7a6a-48d4-8652-526545762b58
- date added to LUP
- 2021-05-20 22:12:47
- date last changed
- 2022-04-27 02:03:26
@article{b1efa33f-7a6a-48d4-8652-526545762b58,
abstract = {{The structures of glycoside hydrolase family 17 (GH17) catalytic modules from modular proteins in the ndvB loci in <i>Pseudomonas aeruginosa</i> (Glt1), <i>P. putida</i> (Glt3) and <i>Bradyrhizobium diazoefficiens</i> (previously <i>B. japonicum</i>) (Glt20) were modeled to shed light on reported differences between these homologous transglycosylases concerning substrate size, preferred cleavage site (from reducing end (Glt20: DP2 product) or non-reducing end (Glt1, Glt3: DP4 products)), branching (Glt20) and linkage formed (1,3-linkage in Glt1, Glt3 and 1,6-linkage in Glt20). Hybrid models were built and stability of the resulting TIM-barrel structures was supported by molecular dynamics simulations. Catalytic amino acids were identified by superimposition of GH17 structures, and function was verified by mutagenesis using Glt20 as template (i.e., E120 and E209). Ligand docking revealed six putative subsites (−4, −3, −2, −1, +1 and +2), and the conserved interacting residues suggest substrate binding in the same orientation in all three transglycosylases, despite release of the donor oligosaccharide product from either the reducing (Glt20) or non-reducing end (Glt1, Gl3). Subsites +1 and +2 are most conserved and the difference in release is likely due to changes in loop structures, leading to loss of hydrogen bonds in Glt20. Substrate docking in Glt20 indicate that presence of covalently bound donor in glycone subsites −4 to −1 creates space to accommodate acceptor oligosaccharide in alternative subsites in the catalytic cleft, promoting a branching point and formation of a 1,6-linkage. The minimum donor size of DP5, can be explained assuming preferred binding of DP4 substrates in subsite −4 to −1, preventing catalysis.}},
author = {{Linares-Pastén, Javier A. and Jonsdottir, Lilja Björk and Hreggvidsson, Gudmundur O. and Fridjonsson, Olafur H. and Watzlawick, Hildegard and Nordberg Karlsson, Eva}},
issn = {{2076-3417}},
keywords = {{transglycosylation; laminarioligosaccharides; transglycosidase; 3D-structure; molecular dynamics; Bradyrhizobium; Pseudomonas}},
language = {{eng}},
month = {{04}},
number = {{9}},
publisher = {{MDPI AG}},
series = {{Applied Sciences (Switzerland)}},
title = {{Modeled 3D-Structures of Proteobacterial Transglycosylases from Glycoside Hydrolase Family 17 Give Insight in Ligand Interactions Explaining Differences in Transglycosylation Products}},
url = {{http://dx.doi.org/10.3390/app11094048}},
doi = {{10.3390/app11094048}},
volume = {{11}},
year = {{2021}},
}