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Pleiotropic Effects of Bacterial Small Alarmone Synthetases: Underscoring the Dual-Domain Small Alarmone Synthetases in Mycobacterium smegmatis
The nucleotide alarmone (p)ppGpp, signaling the stringent response, is known for more than 5 decades. The cellular turnover of the alarmone is regulated by RelA/SpoT homolog (RSH) superfamily of enzymes. There are long RSHs (RelA, SpoT, and Rel) and short RSHs [small alarmone synthetases (SAS) and s...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Media S.A.
2020
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7591505/ https://www.ncbi.nlm.nih.gov/pubmed/33154743 http://dx.doi.org/10.3389/fmicb.2020.594024 |
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author | Krishnan, Sushma Chatterji, Dipankar |
author_facet | Krishnan, Sushma Chatterji, Dipankar |
author_sort | Krishnan, Sushma |
collection | PubMed |
description | The nucleotide alarmone (p)ppGpp, signaling the stringent response, is known for more than 5 decades. The cellular turnover of the alarmone is regulated by RelA/SpoT homolog (RSH) superfamily of enzymes. There are long RSHs (RelA, SpoT, and Rel) and short RSHs [small alarmone synthetases (SAS) and small alarmone hydrolases (SAH)]. Long RSHs are multidomain proteins with (p)ppGpp synthesis, hydrolysis, and regulatory functions. Short RSHs are single-domain proteins with a single (p)ppGpp synthesis/hydrolysis function with few exceptions having two domains. Mycobacterial RelZ is a dual-domain SAS with RNase HII and the (p)ppGpp synthetase activity. SAS is known to impact multiple cellular functions independently and in accordance with the long RSH. Few SAS in bacteria including RelZ synthesize pGpp, the third small alarmone, along with the conventional (p)ppGpp. SAS can act as an RNA-binding protein for the negative allosteric inhibition of (p)ppGpp synthesis. Here, we initially recap the important features and molecular functions of different SAS that are previously characterized to understand the obligation for the “alarmone pool” produced by the long and short RSHs. Then, we focus on the RelZ, especially the combined functions of RNase HII and (p)ppGpp synthesis from a single polypeptide to connect with the recent findings of SAS as an RNA-binding protein. Finally, we conclude with the possibilities of using single-stranded RNA (ssRNA) as an additional therapeutic strategy to combat the persistent infections by inhibiting the redundant (p)ppGpp synthetases. |
format | Online Article Text |
id | pubmed-7591505 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-75915052020-11-04 Pleiotropic Effects of Bacterial Small Alarmone Synthetases: Underscoring the Dual-Domain Small Alarmone Synthetases in Mycobacterium smegmatis Krishnan, Sushma Chatterji, Dipankar Front Microbiol Microbiology The nucleotide alarmone (p)ppGpp, signaling the stringent response, is known for more than 5 decades. The cellular turnover of the alarmone is regulated by RelA/SpoT homolog (RSH) superfamily of enzymes. There are long RSHs (RelA, SpoT, and Rel) and short RSHs [small alarmone synthetases (SAS) and small alarmone hydrolases (SAH)]. Long RSHs are multidomain proteins with (p)ppGpp synthesis, hydrolysis, and regulatory functions. Short RSHs are single-domain proteins with a single (p)ppGpp synthesis/hydrolysis function with few exceptions having two domains. Mycobacterial RelZ is a dual-domain SAS with RNase HII and the (p)ppGpp synthetase activity. SAS is known to impact multiple cellular functions independently and in accordance with the long RSH. Few SAS in bacteria including RelZ synthesize pGpp, the third small alarmone, along with the conventional (p)ppGpp. SAS can act as an RNA-binding protein for the negative allosteric inhibition of (p)ppGpp synthesis. Here, we initially recap the important features and molecular functions of different SAS that are previously characterized to understand the obligation for the “alarmone pool” produced by the long and short RSHs. Then, we focus on the RelZ, especially the combined functions of RNase HII and (p)ppGpp synthesis from a single polypeptide to connect with the recent findings of SAS as an RNA-binding protein. Finally, we conclude with the possibilities of using single-stranded RNA (ssRNA) as an additional therapeutic strategy to combat the persistent infections by inhibiting the redundant (p)ppGpp synthetases. Frontiers Media S.A. 2020-10-14 /pmc/articles/PMC7591505/ /pubmed/33154743 http://dx.doi.org/10.3389/fmicb.2020.594024 Text en Copyright © 2020 Krishnan and Chatterji. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Microbiology Krishnan, Sushma Chatterji, Dipankar Pleiotropic Effects of Bacterial Small Alarmone Synthetases: Underscoring the Dual-Domain Small Alarmone Synthetases in Mycobacterium smegmatis |
title | Pleiotropic Effects of Bacterial Small Alarmone Synthetases: Underscoring the Dual-Domain Small Alarmone Synthetases in Mycobacterium smegmatis |
title_full | Pleiotropic Effects of Bacterial Small Alarmone Synthetases: Underscoring the Dual-Domain Small Alarmone Synthetases in Mycobacterium smegmatis |
title_fullStr | Pleiotropic Effects of Bacterial Small Alarmone Synthetases: Underscoring the Dual-Domain Small Alarmone Synthetases in Mycobacterium smegmatis |
title_full_unstemmed | Pleiotropic Effects of Bacterial Small Alarmone Synthetases: Underscoring the Dual-Domain Small Alarmone Synthetases in Mycobacterium smegmatis |
title_short | Pleiotropic Effects of Bacterial Small Alarmone Synthetases: Underscoring the Dual-Domain Small Alarmone Synthetases in Mycobacterium smegmatis |
title_sort | pleiotropic effects of bacterial small alarmone synthetases: underscoring the dual-domain small alarmone synthetases in mycobacterium smegmatis |
topic | Microbiology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7591505/ https://www.ncbi.nlm.nih.gov/pubmed/33154743 http://dx.doi.org/10.3389/fmicb.2020.594024 |
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