2021
Composition and Biophysical Properties of the Sorting Platform Pods in the Shigella Type III Secretion System
Tachiyama S, Skaar R, Chang Y, Carroll BL, Muthuramalingam M, Whittier SK, Barta ML, Picking WL, Liu J, Picking WD. Composition and Biophysical Properties of the Sorting Platform Pods in the Shigella Type III Secretion System. Frontiers In Cellular And Infection Microbiology 2021, 11: 682635. PMID: 34150677, PMCID: PMC8211105, DOI: 10.3389/fcimb.2021.682635.Peer-Reviewed Original ResearchConceptsType III secretion systemCytoplasmic sorting platformSorting platformSecretion systemTwo-hybrid analysisCryo-electron tomography dataC-terminal domainShigella type III secretion systemFull-length copiesBiophysical propertiesDistinct biophysical propertiesSpa47 ATPaseT3SS injectisomeEffector proteinsSecretion substratesDistinct complexesIntracellular nicheBasal bodiesPrimary virulence factorSpa33Host cellsHeterotrimerPrecise makeupVirulence factorsMxiK
2020
The Structures of SctK and SctD from Pseudomonas aeruginosa Reveal the Interface of the Type III Secretion System Basal Body and Sorting Platform
Muthuramalingam M, Whittier SK, Lovell S, Battaile KP, Tachiyama S, Johnson DK, Picking WL, Picking WD. The Structures of SctK and SctD from Pseudomonas aeruginosa Reveal the Interface of the Type III Secretion System Basal Body and Sorting Platform. Journal Of Molecular Biology 2020, 432: 166693. PMID: 33122003, PMCID: PMC10550303, DOI: 10.1016/j.jmb.2020.10.027.Peer-Reviewed Original ResearchConceptsInner membrane ringBasal bodiesCytoplasmic domainSorting platformFirst high-resolution structureType III secretion systemCytoplasmic sorting platformTwo-hybrid analysisGram-negative bacterial pathogensProtein family membersNormal cellular functionHigh-resolution structuresAtomic resolution modelsHelix-rich structureEukaryotic cellsT3SS apparatusAdaptor proteinCellular functionsSecretion systemMembrane ringMechanistic interfaceTip complexExternal needleRadial spokesProtein
2019
The cytoplasmic domain of MxiG interacts with MxiK and directs assembly of the sorting platform in the Shigella type III secretion system
Tachiyama S, Chang Y, Muthuramalingam M, Hu B, Barta ML, Picking WL, Liu J, Picking WD. The cytoplasmic domain of MxiG interacts with MxiK and directs assembly of the sorting platform in the Shigella type III secretion system. Journal Of Biological Chemistry 2019, 294: 19184-19196. PMID: 31699894, PMCID: PMC6916477, DOI: 10.1074/jbc.ra119.009125.Peer-Reviewed Original ResearchConceptsInner membrane ringType III secretion systemCytoplasmic domainSecretion systemCytoplasmic sorting platformForkhead-associated (FHA) domainShigella type III secretion systemDiverse bacterial pathogensDisruption of interactionsSpa47 ATPaseStructure-function relationshipsExtracellular needleEffector recognitionGram-negative bacteriaEukaryotic cellsT3SS apparatusVirulence effectorsMembrane ringSorting platformInsertional mutagenesisGenetic methodsHomologous interactionsMxiKTip complexBasal bodies
2018
Using disruptive insertional mutagenesis to identify the in situ structure‐function landscape of the Shigella translocator protein IpaB
Barta ML, Tachiyama S, Muthuramalingam M, Arizmendi O, Villanueva CE, Ramyar KX, Geisbrecht BV, Lovell S, Battaile KP, Picking WL, Picking WD. Using disruptive insertional mutagenesis to identify the in situ structure‐function landscape of the Shigella translocator protein IpaB. Protein Science 2018, 27: 1392-1406. PMID: 29672980, PMCID: PMC6153406, DOI: 10.1002/pro.3428.Peer-Reviewed Original ResearchConceptsTip complexInsertional mutagenesisTranslocator protein IpaBBacterial type III secretion systemType III secretion systemC-terminal halfN-terminal halfInsertion mutantsT3SS apparatusCellular functionsLatter mutantSecretion inductionMammalian cellsSecretion systemTC functionHost membraneBasal bodiesBacteriophage T4 lysozymeTertiary structureImpaired interactionIpaBPore formationT4 lysozymeBacterial surfaceMutants