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Characterization of an aspartate aminotransferase encoded by YPO0623 with frequent nonsense mutations in Yersinia pestis

Authors :
Junyan Jin
Liting Xiao
Yarong Wu
Zhulin Sun
Ziyao Xiong
Yanbing Li
Yanting Zhao
Wenwu Yao
Leiming Shen
Yiming Cui
Yafang Tan
Yanping Han
Zongmin Du
Yujun Cui
Ruifu Yang
Kai Song
Yajun Song
Source :
Frontiers in Cellular and Infection Microbiology, Vol 13 (2023)
Publication Year :
2023
Publisher :
Frontiers Media S.A., 2023.

Abstract

Yersinia pestis, the causative agent of plague, is a genetically monomorphic bacterial pathogen that evolved from Yersinia pseudotuberculosis approximately 7,400 years ago. We observed unusually frequent mutations in Y. pestis YPO0623, mostly resulting in protein translation termination, which implies a strong natural selection. These mutations were found in all phylogenetic lineages of Y. pestis, and there was no apparent pattern in the spatial distribution of the mutant strains. Based on these findings, we aimed to investigate the biological function of YPO0623 and the reasons for its frequent mutation in Y. pestis. Our in vitro and in vivo assays revealed that the deletion of YPO0623 enhanced the growth of Y. pestis in nutrient-rich environments and led to increased tolerance to heat and cold shocks. With RNA-seq analysis, we also discovered that the deletion of YPO0623 resulted in the upregulation of genes associated with the type VI secretion system (T6SS) at 26°C, which probably plays a crucial role in the response of Y. pestis to environment fluctuations. Furthermore, bioinformatic analysis showed that YPO0623 has high homology with a PLP-dependent aspartate aminotransferase in Salmonella enterica, and the enzyme activity assays confirmed its aspartate aminotransferase activity. However, the enzyme activity of YPO0623 was significantly lower than that in other bacteria. These observations provide some insights into the underlying reasons for the high-frequency nonsense mutations in YPO0623, and further investigations are needed to determine the exact mechanism.

Details

Language :
English
ISSN :
22352988
Volume :
13
Database :
Directory of Open Access Journals
Journal :
Frontiers in Cellular and Infection Microbiology
Publication Type :
Academic Journal
Accession number :
edsdoj.fd8bb82349c1479cbca659d638f302e7
Document Type :
article
Full Text :
https://doi.org/10.3389/fcimb.2023.1288371