skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Engineering a monolignol 4- O-methyltransferase with high selectivity for the condensed lignin precursor coniferyl alchohol

Abstract

Lignin, a rigid biopolymer in plant cell walls, is derived from the oxidative polymerization of three monolignols. The composition of monolignol monomers dictates the degree of lignin condensation, reactivity, and thus the degradability of plant cell walls. Guaiacyl lignin is regarded as the condensed structural unit. Polymerization of lignin is initiated through the deprotonation of the para-hydroxyl group of monolignols. Therefore, preferentially modifying the para-hydroxyl of a specific monolignol to deprive its dehydrogenation propensity would disturb the formation of particular lignin subunits. Here, we test the hypothesis that specific remodeling the active site of a monolignol 4-O-methyltransferase would create an enzyme that specifically methylates the condensed guaiacyl lignin precursor coniferyl alcohol. Combining crystal structural information with combinatorial active site saturation mutagenesis and starting with the engineered promiscuous enzyme, MOMT5 (T133L/E165I/F175I/F166W/H169F), we incrementally remodeled its substrate binding pocket by the addition of four substitutions, i.e. M26H, S30R, V33S, and T319M, yielding a mutant enzyme capable of discriminately etherifying the para-hydroxyl of coniferyl alcohol even in the presence of excess sinapyl alcohol. The engineered enzyme variant has a substantially reduced substrate binding pocket that imposes a clear steric hindrance thereby excluding bulkier lignin precursors. Lastly, the resulting enzyme variant represents an excellentmore » candidate for modulating lignin composition and/or structure in planta.« less

Authors:
 [1];  [1];  [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1235889
Report Number(s):
BNL-111732-2016-JA
Journal ID: ISSN 0021-9258; KC0304020
Grant/Contract Number:  
SC00112704
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Biological Chemistry
Additional Journal Information:
Journal Volume: 290; Journal Issue: 44; Journal ID: ISSN 0021-9258
Publisher:
American Society for Biochemistry and Molecular Biology
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; monolignol; 4-O-methyltransferase; lignin; crystal structure; directed evolution; mutagenesis; plant cell wall; protein engineering

Citation Formats

Cai, Yuanheng, Shanklin, John, Mohammad -Wadud Bhuiya, and Liu, Chang -Jun. Engineering a monolignol 4-O-methyltransferase with high selectivity for the condensed lignin precursor coniferyl alchohol. United States: N. p., 2015. Web. doi:10.1074/jbc.M115.684217.
Cai, Yuanheng, Shanklin, John, Mohammad -Wadud Bhuiya, & Liu, Chang -Jun. Engineering a monolignol 4-O-methyltransferase with high selectivity for the condensed lignin precursor coniferyl alchohol. United States. doi:10.1074/jbc.M115.684217.
Cai, Yuanheng, Shanklin, John, Mohammad -Wadud Bhuiya, and Liu, Chang -Jun. Wed . "Engineering a monolignol 4-O-methyltransferase with high selectivity for the condensed lignin precursor coniferyl alchohol". United States. doi:10.1074/jbc.M115.684217. https://www.osti.gov/servlets/purl/1235889.
@article{osti_1235889,
title = {Engineering a monolignol 4-O-methyltransferase with high selectivity for the condensed lignin precursor coniferyl alchohol},
author = {Cai, Yuanheng and Shanklin, John and Mohammad -Wadud Bhuiya and Liu, Chang -Jun},
abstractNote = {Lignin, a rigid biopolymer in plant cell walls, is derived from the oxidative polymerization of three monolignols. The composition of monolignol monomers dictates the degree of lignin condensation, reactivity, and thus the degradability of plant cell walls. Guaiacyl lignin is regarded as the condensed structural unit. Polymerization of lignin is initiated through the deprotonation of the para-hydroxyl group of monolignols. Therefore, preferentially modifying the para-hydroxyl of a specific monolignol to deprive its dehydrogenation propensity would disturb the formation of particular lignin subunits. Here, we test the hypothesis that specific remodeling the active site of a monolignol 4-O-methyltransferase would create an enzyme that specifically methylates the condensed guaiacyl lignin precursor coniferyl alcohol. Combining crystal structural information with combinatorial active site saturation mutagenesis and starting with the engineered promiscuous enzyme, MOMT5 (T133L/E165I/F175I/F166W/H169F), we incrementally remodeled its substrate binding pocket by the addition of four substitutions, i.e. M26H, S30R, V33S, and T319M, yielding a mutant enzyme capable of discriminately etherifying the para-hydroxyl of coniferyl alcohol even in the presence of excess sinapyl alcohol. The engineered enzyme variant has a substantially reduced substrate binding pocket that imposes a clear steric hindrance thereby excluding bulkier lignin precursors. Lastly, the resulting enzyme variant represents an excellent candidate for modulating lignin composition and/or structure in planta.},
doi = {10.1074/jbc.M115.684217},
journal = {Journal of Biological Chemistry},
issn = {0021-9258},
number = 44,
volume = 290,
place = {United States},
year = {2015},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 1 work
Citation information provided by
Web of Science

Save / Share: