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.

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.

OBJECTIVE: To explore the clinical characteristics and genetic basis of a child with Teebi hypertelorism syndrome 1 (TBHS1). METHODS: A child with TBHS1 who was admitted to the Children's Medical Center Affiliated to Shanghai Jiao Tong University School of Medicine on July 13, 2021 was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: The child, a 13-year-old male, had manifested delayed growth and development. WES results revealed that he has harbored a heterozygous c.1244A>G variant of the SPECC1L gene, which was verified to be de novo in origin. The variant has not been included in the HGMD and gnomAD databases. As predicted by online software including PolyPhen-2, SIFT, and Mutation Taster, the variant may affect the function of protein domain. And PyMOL software has predicted that the structural stability of SPECC1L protein (p.Gln415Arg) might be reduced. Based on the guidelines of the American College of Medical Genetics and Genomics (ACMG), the variant was classified as pathogenic (PM6+PM1+PP4+PM2_Supporting+PP3). CONCLUSION The heterozygous c.1244A>G variant of the SPECC1L gene probably underlay the TBHS1 in this child. Above finding has expanded the genotypic and phenotypic spectrum of the SPECC1L gene and provided a basis for the clinical diagnosis of this child.
Adolescent ; Humans ; Male ; China ; Computational Biology ; Genomics ; Genotype ; Mutation

OBJECTIVETo analyze clinical manifestations and genetic mutation in a child with severe short stature and other malformations.

METHODSThe child has undergone history taking and physical examination. Genome DNA was extracted from peripheral blood samples of the proband and her family members. Candidate genes were captured with Agilent SureSelect and sequenced on an Illumina platform. Suspected mutation was verified by Sanger sequencing.

RESULTSThe patient, a six-year-and-10-month old girl, presented with non-symmetrical short stature, dysmorphism, abnormalities of limbs and spine, amblyopia of left eye, and cataract of right eye, in addition with frequent respiratory infection and micturition. Laboratory testing suggested 25-hydroxy vitamin D deficiency (18.9 ng/mL). Spine X-ray showed multiple malformations with centrums. Her mother also featured short stature (138 cm). Her aunt had short stature (130 cm) and limb-length discrepancy. Her little brother was 2.5 years old, and his height was 81 cm (-3.4 SD). Exome sequencing revealed a heterozygous mutation c.184C to T (p.Arg62Trp) in the proband and her mother. The same mutation was not found in her father and brother.

CONCLUSIONThe patient was diagnosed with X-linked chondrodysplasia punctata 2. Mutation of the EBP gene probably underlied the disease in this family.