PXD062828

PXD062828 is an original dataset announced via ProteomeXchange.

Title	Neutralization mechanism of a HipA-like toxin targeting isoleucyl-tRNA synthetase
Description	HipAB is a type II toxin-antitoxin (TA) system that targets and inactivates specific aminoacyl-tRNA synthetases in response to various stresses. While the molecular targets and neutralization mechanisms of several HipAB-like TA systems have been well characterized, their structural and functional diversity remains less understood. In this study, we investigated a HipAB-like module (HipABpf) from Pseudomonas fluorescens, where the HipBpf antitoxin features a long, disordered C-terminal region in the absence of HipApf. Using a combination of X-ray crystallography, AlphaFold modeling and mutagenesis assays, we show that upon binding to HipApf, part of this C-terminal region forms two α-helices that are essential for both the interaction with and neutralization of the HipApf toxin. Importantly, HipBpf binding blocks the ATP binding sites of HipApf, potentially by inducing a conformational change in the HipApf N1 subdomain via its C-terminal α6 helix. We also discovered that HipApf phosphorylates the isoleucyl-tRNA synthetase at Ser604, strongly inhibiting its aminoacylation activity. Finally, we demonstrated that the HipABpf system plays a role in coping with oxidative stress and carbon starvation. Taken together, our findings reveal the critical role of the HipBpf C-terminal region in toxin binding and neutralization, while also highlighting the evolutionarily divergent substrate preferences of HipA-like toxins.
HostingRepository	iProX
AnnounceDate	2025-04-11
AnnouncementXML	Submission_2025-04-10_20:41:04.076.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Siping Zhang
SpeciesList	scientific name: Escherichia coli K-12; NCBI TaxID: 83333;
ModificationList	phosphorylated residue
Instrument	Orbitrap Fusion Lumos

Revision	Datetime	Status	ChangeLog Entry
0	2025-04-10 20:40:52	ID requested
⏵ 1	2025-04-10 20:41:04	announced

Dataset with its publication pending

submitter keyword: HipAB system,Pseudomonas fluorescens,Phosphorylation,Neutralization mechanism

Yongxing He
contact affiliation	Lanzhou University
contact email	heyx@lzu.edu.cn
lab head
Siping Zhang
contact affiliation	Lanzhou University
contact email	zhangsp2015@lzu.edu.cn
dataset submitter

iProX dataset URI