Bioinformatics analysis and interaction partners of the PaaX protein associated with Mycobacterium tuberculosis persistence

Yue ZHU; Yuma YANG; Shuming ZHANG; Kuokuo CHEN; Xiting LIN; Taiyun YUE; Xiumin GU; Shicheng XIA; Yanhui YANG

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Bioinformatics analysis and interaction partners of the PaaX protein associated with Mycobacterium tuberculosis persistence

VernacularTitle:结核分枝杆菌持留相关PaaX蛋白的生物信息学分析及互作鉴定
Author: Yue ZHU ¹ ; Yuma YANG ¹ ; Shuming ZHANG ¹ ; Kuokuo CHEN ¹ ; Xiting LIN ¹ ; Taiyun YUE ¹ ; Xiumin GU ¹ ; Shicheng XIA ¹ ; Yanhui YANG ¹
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1. 宁夏医科大学基础医学院,银川 750004
Publication Type:Journal Article
Keywords: Mycobacterium tuberculosis; PaaX protein; bioinformatics analysis; bacterial adenylate cyclase-based two hybrid(BACTH)technology
From: Chinese Journal of Zoonoses 2025;41(8):838-844
CountryChina
Language:Chinese
Abstract: This study was aimed at predicting and analyzing the structural and functional properties of the persistence-associated secretory protein PaaX in Mycobacterium tuberculosis(M.tb),identifying its interacting partners,and elucidating its biological roles.Bioinformatics analysis revealed that PaaX comprises 240 amino acids with a molecular mass of 26.54 kDa(C1158H1866N354O334S14).The protein lacks transmembrane domains but contains a signal peptide.Its secondary structure is dominated by α-helices(53.33%),fol-lowed by random coils(36.25%)and extended strands(10.42%),thereby forming a homotetrameric spatial configuration.Potential PaaX-interacting proteins,including Rv0406c,EchA4,EchA5,HsaE,FadE8,LpqP,and End,were predicted.These candidate genes and the paaX gene were cloned into bacterial two-hybrid vectors and co-transformed into Escherichia coli BTH101 cells.Colony PCR and sequencing confirmed the accuracy of the recombinant constructs.Bacterial two-hybrid assays demonstrated direct interac-tions of PaaX with EchA4,HsaE,FadE8,and LpqP.Moreover,gradient dilution experiments indicated that the strongest binding af-finity occurred between PaaX and EchA4.AlphaFold 3 modeling further validated these interactions,thus providing high-confidence predictions of binding interfaces.Our findings revealed that PaaX,a secreted α-helix-rich protein,engages in specific interactions with key metabolic enzymes(EchA4,HsaE,and FadE8)and a lipoprotein(LpqP),thus suggesting its potential involvement in lipid metabolism,stress adaptation,and host-pathogen interactions.This study provides novel insights into PaaX's contribution to M.tb per-sistence and pathogenicity,and highlights its value as a potential target for tuberculosis diagnostics and therapeutic development.