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Mechanistic insights into substrate recognition and catalysis of a new ulvan lyase of polysaccharide lyase family 24
Citation
Xu, F and Dong, F and Sun, X-H and Cao, H-Y and Fu, H-H and Li, C-Y and Zhang, X-Y and McMinn, A and Zhang, Y-Z and Wang, P and Chen, X-L, Mechanistic insights into substrate recognition and catalysis of a new ulvan lyase of polysaccharide lyase family 24, Applied and Environmental Microbiology, 87, (12) Article e00412-21. ISSN 1098-5336 (2021) [Refereed Article]
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Copyright © 2021 American Society for Microbiology. All Rights Reserved.
Abstract
Ulvan is an important marine polysaccharide. Bacterial ulvan lyases play important roles in ulvan degradation and marine carbon cycling. Until now, only a small number of ulvan lyases have been characterized. Here, a new ulvan lyase, Uly1, belonging to polysaccharide lyase family 24 (PL24) from the marine bacterium Catenovulum maritimum, is characterized. The optimal temperature and pH for Uly1 to degrade ulvan are 40°C and pH 9.0, respectively. Uly1 degrades ulvan polysaccharides in the endolytic manner, mainly producing ΔRha3S, consisting of an unsaturated 4-deoxy-l-threo-hex-4-enopyranosiduronic acid and a 3-O-sulfated α-l-rhamnose. The structure of Uly1 was resolved at a 2.10-Å resolution. Uly1 adopts a seven-bladed β-propeller architecture. Structural and site-directed mutagenesis analyses indicate that four highly conserved residues, H128, H149, Y223, and R239, are essential for catalysis. H128 functions as both the catalytic acid and base, H149 and R239 function as the neutralizers, and Y223 plays a supporting role in catalysis. Structural comparison and sequence alignment suggest that Uly1 and many other PL24 enzymes may directly bind the substrate near the catalytic residues for catalysis, different from the PL24 ulvan lyase LOR_107, which adopts a two-stage substrate binding process. This study provides new insights into ulvan lyases and ulvan degradation.
Item Details
Item Type: | Refereed Article |
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Keywords: | ulvan, ulvan lyase, polysaccharide lyase family 24, marine bacterium, substrate recognition, catalytic mechanism |
Research Division: | Biological Sciences |
Research Group: | Microbiology |
Research Field: | Microbial ecology |
Objective Division: | Environmental Management |
Objective Group: | Marine systems and management |
Objective Field: | Oceanic processes (excl. in the Antarctic and Southern Ocean) |
UTAS Author: | McMinn, A (Professor Andrew McMinn) |
ID Code: | 145529 |
Year Published: | 2021 |
Web of Science® Times Cited: | 1 |
Deposited By: | Ecology and Biodiversity |
Deposited On: | 2021-07-26 |
Last Modified: | 2021-11-22 |
Downloads: | 0 |
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