Complex Loop Dynamics Underpin Activity, Specificity, and Evolvability in the (βα)8 Barrel Enzymes of Histidine and Tryptophan Biosynthesis
Romero-Rivera, Adrian ; Corbella, Marina ; Parracino, Antonietta ; Patrick, Wayne M and Kamerlin, Shina Caroline Lynn LU
(2022)
In JACS Au
2(4).
p.943-960
- Abstract
Enzymes are conformationally dynamic, and their dynamical properties play an important role in regulating their specificity and evolvability. In this context, substantial attention has been paid to the role of ligand-gated conformational changes in enzyme catalysis; however, such studies have focused on tremendously proficient enzymes such as triosephosphate isomerase and orotidine 5'-monophosphate decarboxylase, where the rapid (μs timescale) motion of a single loop dominates the transition between catalytically inactive and active conformations. In contrast, the (βα)8-barrels of tryptophan and histidine biosynthesis, such as the specialist isomerase enzymes HisA and TrpF, and the bifunctional isomerase PriA, are decorated by multiple... (More)
Enzymes are conformationally dynamic, and their dynamical properties play an important role in regulating their specificity and evolvability. In this context, substantial attention has been paid to the role of ligand-gated conformational changes in enzyme catalysis; however, such studies have focused on tremendously proficient enzymes such as triosephosphate isomerase and orotidine 5'-monophosphate decarboxylase, where the rapid (μs timescale) motion of a single loop dominates the transition between catalytically inactive and active conformations. In contrast, the (βα)8-barrels of tryptophan and histidine biosynthesis, such as the specialist isomerase enzymes HisA and TrpF, and the bifunctional isomerase PriA, are decorated by multiple long loops that undergo conformational transitions on the ms (or slower) timescale. Studying the interdependent motions of multiple slow loops, and their role in catalysis, poses a significant computational challenge. This work combines conventional and enhanced molecular dynamics simulations with empirical valence bond simulations to provide rich details of the conformational behavior of the catalytic loops in HisA, PriA, and TrpF, and the role of their plasticity in facilitating bifunctionality in PriA and evolved HisA variants. In addition, we demonstrate that, similar to other enzymes activated by ligand-gated conformational changes, loops 3 and 4 of HisA and PriA act as gripper loops, facilitating the isomerization of the large bulky substrate ProFAR, albeit now on much slower timescales. This hints at convergent evolution on these different (βα)8-barrel scaffolds. Finally, our work reemphasizes the potential of engineering loop dynamics as a tool to artificially manipulate the catalytic repertoire of TIM-barrel proteins.
(Less)
- author
- Romero-Rivera, Adrian
; Corbella, Marina
; Parracino, Antonietta
; Patrick, Wayne M
and Kamerlin, Shina Caroline Lynn
LU
- publishing date
- 2022-04-25
- type
- Contribution to journal
- publication status
- published
- in
- JACS Au
- volume
- 2
- issue
- 4
- pages
- 18 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:35557756
- scopus:85129327568
- ISSN
- 2691-3704
- DOI
- 10.1021/jacsau.2c00063
- language
- English
- LU publication?
- no
- additional info
- © 2022 The Authors. Published by American Chemical Society.
- id
- 9246f94d-e4c0-45f4-b6de-145a1be7ff57
- date added to LUP
- 2025-01-11 18:46:47
- date last changed
- 2025-07-13 18:39:57
@article{9246f94d-e4c0-45f4-b6de-145a1be7ff57,
abstract = {{<p>Enzymes are conformationally dynamic, and their dynamical properties play an important role in regulating their specificity and evolvability. In this context, substantial attention has been paid to the role of ligand-gated conformational changes in enzyme catalysis; however, such studies have focused on tremendously proficient enzymes such as triosephosphate isomerase and orotidine 5'-monophosphate decarboxylase, where the rapid (μs timescale) motion of a single loop dominates the transition between catalytically inactive and active conformations. In contrast, the (βα)8-barrels of tryptophan and histidine biosynthesis, such as the specialist isomerase enzymes HisA and TrpF, and the bifunctional isomerase PriA, are decorated by multiple long loops that undergo conformational transitions on the ms (or slower) timescale. Studying the interdependent motions of multiple slow loops, and their role in catalysis, poses a significant computational challenge. This work combines conventional and enhanced molecular dynamics simulations with empirical valence bond simulations to provide rich details of the conformational behavior of the catalytic loops in HisA, PriA, and TrpF, and the role of their plasticity in facilitating bifunctionality in PriA and evolved HisA variants. In addition, we demonstrate that, similar to other enzymes activated by ligand-gated conformational changes, loops 3 and 4 of HisA and PriA act as gripper loops, facilitating the isomerization of the large bulky substrate ProFAR, albeit now on much slower timescales. This hints at convergent evolution on these different (βα)8-barrel scaffolds. Finally, our work reemphasizes the potential of engineering loop dynamics as a tool to artificially manipulate the catalytic repertoire of TIM-barrel proteins.</p>}},
author = {{Romero-Rivera, Adrian and Corbella, Marina and Parracino, Antonietta and Patrick, Wayne M and Kamerlin, Shina Caroline Lynn}},
issn = {{2691-3704}},
language = {{eng}},
month = {{04}},
number = {{4}},
pages = {{943--960}},
publisher = {{The American Chemical Society (ACS)}},
series = {{JACS Au}},
title = {{Complex Loop Dynamics Underpin Activity, Specificity, and Evolvability in the (βα)<sub>8</sub> Barrel Enzymes of Histidine and Tryptophan Biosynthesis}},
url = {{http://dx.doi.org/10.1021/jacsau.2c00063}},
doi = {{10.1021/jacsau.2c00063}},
volume = {{2}},
year = {{2022}},
}