Ribosome association primes the stringent factor Rel for tRNA-dependent locking in the A-site and activation of (p)ppGpp synthesis
(2021) In Nucleic Acids Research 49(1). p.444-457- Abstract
In the Gram-positive Firmicute bacterium Bacillus subtilis, amino acid starvation induces synthesis of the alarmone (p)ppGpp by the RelA/SpoT Homolog factor Rel. This bifunctional enzyme is capable of both synthesizing and hydrolysing (p)ppGpp. To detect amino acid deficiency, Rel monitors the aminoacylation status of the ribosomal A-site tRNA by directly inspecting the tRNA's CCA end. Here we dissect the molecular mechanism of B. subtilis Rel. Off the ribosome, Rel predominantly assumes a 'closed' conformation with dominant (p)ppGpp hydrolysis activity. This state does not specifically select deacylated tRNA since the interaction is only moderately affected by tRNA aminoacylation. Once bound to the vacant ribosomal A-site, Rel assumes... (More)
In the Gram-positive Firmicute bacterium Bacillus subtilis, amino acid starvation induces synthesis of the alarmone (p)ppGpp by the RelA/SpoT Homolog factor Rel. This bifunctional enzyme is capable of both synthesizing and hydrolysing (p)ppGpp. To detect amino acid deficiency, Rel monitors the aminoacylation status of the ribosomal A-site tRNA by directly inspecting the tRNA's CCA end. Here we dissect the molecular mechanism of B. subtilis Rel. Off the ribosome, Rel predominantly assumes a 'closed' conformation with dominant (p)ppGpp hydrolysis activity. This state does not specifically select deacylated tRNA since the interaction is only moderately affected by tRNA aminoacylation. Once bound to the vacant ribosomal A-site, Rel assumes an 'open' conformation, which primes its TGS and Helical domains for specific recognition and stabilization of cognate deacylated tRNA on the ribosome. The tRNA locks Rel on the ribosome in a hyperactivated state that processively synthesises (p)ppGpp while the hydrolysis is suppressed. In stark contrast to non-specific tRNA interactions off the ribosome, tRNA-dependent Rel locking on the ribosome and activation of (p)ppGpp synthesis are highly specific and completely abrogated by tRNA aminoacylation. Binding pppGpp to a dedicated allosteric site located in the N-terminal catalytic domain region of the enzyme further enhances its synthetase activity.
(Less)
- author
- Takada, Hiraku
; Roghanian, Mohammad
; Caballero-Montes, Julien
; Van Nerom, Katleen
; Jimmy, Steffi
; Kudrin, Pavel
; Trebini, Fabio
; Murayama, Rikinori
; Akanuma, Genki
; Garcia-Pino, Abel
and Hauryliuk, Vasili
LU
(Less) - publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- in
- Nucleic Acids Research
- volume
- 49
- issue
- 1
- pages
- 444 - 457
- publisher
- Oxford University Press
- external identifiers
-
- scopus:85099721919
- pmid:33330919
- ISSN
- 0305-1048
- DOI
- 10.1093/nar/gkaa1187
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2021 The Author(s) 2020. Published by Oxford University Press on behalf of Nucleic Acids Research. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
- id
- e577054b-bd18-4d03-93b8-9a9344d3cf99
- date added to LUP
- 2021-09-24 20:30:05
- date last changed
- 2024-06-16 19:29:21
@article{e577054b-bd18-4d03-93b8-9a9344d3cf99,
abstract = {{<p>In the Gram-positive Firmicute bacterium Bacillus subtilis, amino acid starvation induces synthesis of the alarmone (p)ppGpp by the RelA/SpoT Homolog factor Rel. This bifunctional enzyme is capable of both synthesizing and hydrolysing (p)ppGpp. To detect amino acid deficiency, Rel monitors the aminoacylation status of the ribosomal A-site tRNA by directly inspecting the tRNA's CCA end. Here we dissect the molecular mechanism of B. subtilis Rel. Off the ribosome, Rel predominantly assumes a 'closed' conformation with dominant (p)ppGpp hydrolysis activity. This state does not specifically select deacylated tRNA since the interaction is only moderately affected by tRNA aminoacylation. Once bound to the vacant ribosomal A-site, Rel assumes an 'open' conformation, which primes its TGS and Helical domains for specific recognition and stabilization of cognate deacylated tRNA on the ribosome. The tRNA locks Rel on the ribosome in a hyperactivated state that processively synthesises (p)ppGpp while the hydrolysis is suppressed. In stark contrast to non-specific tRNA interactions off the ribosome, tRNA-dependent Rel locking on the ribosome and activation of (p)ppGpp synthesis are highly specific and completely abrogated by tRNA aminoacylation. Binding pppGpp to a dedicated allosteric site located in the N-terminal catalytic domain region of the enzyme further enhances its synthetase activity.</p>}},
author = {{Takada, Hiraku and Roghanian, Mohammad and Caballero-Montes, Julien and Van Nerom, Katleen and Jimmy, Steffi and Kudrin, Pavel and Trebini, Fabio and Murayama, Rikinori and Akanuma, Genki and Garcia-Pino, Abel and Hauryliuk, Vasili}},
issn = {{0305-1048}},
language = {{eng}},
number = {{1}},
pages = {{444--457}},
publisher = {{Oxford University Press}},
series = {{Nucleic Acids Research}},
title = {{Ribosome association primes the stringent factor Rel for tRNA-dependent locking in the A-site and activation of (p)ppGpp synthesis}},
url = {{http://dx.doi.org/10.1093/nar/gkaa1187}},
doi = {{10.1093/nar/gkaa1187}},
volume = {{49}},
year = {{2021}},
}