[English] 日本語
Yorodumi
- PDB-9xw8: Cryo-EM structure of PI3Kalpha E542K mutation in complex with STX-478 -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: PDB / ID: 9xw8
TitleCryo-EM structure of PI3Kalpha E542K mutation in complex with STX-478
ComponentsPhosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoform
KeywordsSTRUCTURAL PROTEIN / Phosphoinositide 3-kinase / drug target / ligand / binding pocket / hotspot mutation / allosteric inhbitor
Function / homology
Function and homology information


response to muscle inactivity / regulation of actin filament organization / response to butyrate / negative regulation of actin filament depolymerization / IRS-mediated signalling / PI3K events in ERBB4 signaling / response to L-leucine / cellular response to hydrostatic pressure / Activated NTRK2 signals through PI3K / Activated NTRK3 signals through PI3K ...response to muscle inactivity / regulation of actin filament organization / response to butyrate / negative regulation of actin filament depolymerization / IRS-mediated signalling / PI3K events in ERBB4 signaling / response to L-leucine / cellular response to hydrostatic pressure / Activated NTRK2 signals through PI3K / Activated NTRK3 signals through PI3K / phosphatidylinositol 3-kinase complex, class IB / phosphatidylinositol 3-kinase complex / Co-stimulation by ICOS / TORC2 signaling / positive regulation of protein localization to membrane / Signaling by cytosolic FGFR1 fusion mutants / vasculature development / Nephrin family interactions / Signaling by LTK in cancer / 1-phosphatidylinositol-4-phosphate 3-kinase activity / Signaling by LTK / anoikis / phosphatidylinositol 3-kinase complex, class IA / MET activates PI3K/AKT signaling / PI3K/AKT activation / phosphatidylinositol-4,5-bisphosphate 3-kinase / 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity / relaxation of cardiac muscle / phosphatidylinositol 3-kinase / Signaling by ALK / phosphatidylinositol-3-phosphate biosynthetic process / cardiac muscle cell contraction / vascular endothelial growth factor signaling pathway / 1-phosphatidylinositol-3-kinase activity / Erythropoietin activates Phosphoinositide-3-kinase (PI3K) / PI-3K cascade:FGFR3 / response to dexamethasone / PI-3K cascade:FGFR2 / PI-3K cascade:FGFR4 / PI-3K cascade:FGFR1 / phosphatidylinositol phosphate biosynthetic process / Synthesis of PIPs at the plasma membrane / positive regulation of protein kinase activity / response to muscle stretch / phosphatidylinositol-mediated signaling / RET signaling / negative regulation of anoikis / Interleukin-3, Interleukin-5 and GM-CSF signaling / PI3K events in ERBB2 signaling / insulin receptor substrate binding / PI3K Cascade / Role of LAT2/NTAL/LAB on calcium mobilization / RAC2 GTPase cycle / Interleukin receptor SHC signaling / intercalated disc / Role of phospholipids in phagocytosis / CD28 dependent PI3K/Akt signaling / GAB1 signalosome / endothelial cell migration / protein kinase activator activity / negative regulation of macroautophagy / positive regulation of lamellipodium assembly / cardiac muscle contraction / GPVI-mediated activation cascade / Signaling by PDGFRA transmembrane, juxtamembrane and kinase domain mutants / Signaling by PDGFRA extracellular domain mutants / insulin-like growth factor receptor signaling pathway / Signaling by FGFR4 in disease / Signaling by FLT3 ITD and TKD mutants / RAC1 GTPase cycle / Signaling by FGFR3 in disease / Tie2 Signaling / Signaling by FGFR2 in disease / Signaling by FLT3 fusion proteins / positive regulation of smooth muscle cell proliferation / FLT3 Signaling / Signaling by FGFR1 in disease / positive regulation of TOR signaling / Downstream signal transduction / response to activity / Signaling by phosphorylated juxtamembrane, extracellular and kinase domain KIT mutants / phosphatidylinositol 3-kinase/protein kinase B signal transduction / Regulation of signaling by CBL / platelet activation / Constitutive Signaling by EGFRvIII / Signaling by SCF-KIT / Signaling by ERBB2 ECD mutants / Signaling by ERBB2 KD Mutants / VEGFA-VEGFR2 Pathway / insulin receptor signaling pathway / T cell receptor signaling pathway / epidermal growth factor receptor signaling pathway / Constitutive Signaling by Aberrant PI3K in Cancer / Signaling by CSF1 (M-CSF) in myeloid cells / actin cytoskeleton organization / cellular response to insulin stimulus / Signaling by ALK fusions and activated point mutants / DAP12 signaling / PIP3 activates AKT signaling / cell migration
Similarity search - Function
PI3Kalpha, catalytic domain / PI3-kinase family, p85-binding domain / PI3-kinase family, p85-binding domain / Phosphatidylinositol 3-kinase, adaptor-binding domain / Phosphatidylinositol 3-kinase adaptor-binding (PI3K ABD) domain profile. / PI3-kinase family, Ras-binding domain / Phosphatidylinositol 3-kinase Ras-binding (PI3K RBD) domain / PI3-kinase family, ras-binding domain / Phosphatidylinositol 3-kinase Ras-binding (PI3K RBD) domain profile. / C2 phosphatidylinositol 3-kinase-type domain ...PI3Kalpha, catalytic domain / PI3-kinase family, p85-binding domain / PI3-kinase family, p85-binding domain / Phosphatidylinositol 3-kinase, adaptor-binding domain / Phosphatidylinositol 3-kinase adaptor-binding (PI3K ABD) domain profile. / PI3-kinase family, Ras-binding domain / Phosphatidylinositol 3-kinase Ras-binding (PI3K RBD) domain / PI3-kinase family, ras-binding domain / Phosphatidylinositol 3-kinase Ras-binding (PI3K RBD) domain profile. / C2 phosphatidylinositol 3-kinase-type domain / Phosphoinositide 3-kinase C2 / C2 phosphatidylinositol 3-kinase (PI3K)-type domain profile. / Phosphoinositide 3-kinase, region postulated to contain C2 domain / Phosphoinositide 3-kinase family, accessory domain (PIK domain) / Phosphoinositide 3-kinase family, accessory domain (PIK domain) / Phosphoinositide 3-kinase, accessory (PIK) domain superfamily / Phosphoinositide 3-kinase, accessory (PIK) domain / Phosphatidylinositol kinase / PIK helical domain profile. / Phosphatidylinositol 3- and 4-kinases signature 1. / Phosphatidylinositol 3/4-kinase, conserved site / Phosphatidylinositol 3- and 4-kinases signature 2. / Phosphatidylinositol 3-/4-kinase, catalytic domain superfamily / Phosphoinositide 3-kinase, catalytic domain / Phosphatidylinositol 3- and 4-kinase / Phosphatidylinositol 3- and 4-kinases catalytic domain profile. / Phosphatidylinositol 3-/4-kinase, catalytic domain / C2 domain superfamily / Armadillo-type fold / Ubiquitin-like domain superfamily / Protein kinase-like domain superfamily
Similarity search - Domain/homology
Chem-ZWE / Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoform
Similarity search - Component
Biological speciesHomo sapiens (human)
MethodELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.86 Å
AuthorsLiu, X. / Chen, Y. / Li, G. / Chen, A. / Zhou, Q. / Wang, M.-W.
Funding support China, 5items
OrganizationGrant numberCountry
National Natural Science Foundation of China (NSFC)82273961 China
National Natural Science Foundation of China (NSFC)82073904 China
National Natural Science Foundation of China (NSFC)81872915 China
Other government China
Other government China
CitationJournal: Acta Pharm Sin B / Year: 2026
Title: Molecular architecture responsible for specific inhibition of oncogenic PI3K mutants by RLY-2608 and STX-478.
Authors: Xiao Liu / Yanyan Chen / Guanyi Li / Anqi Chen / Qingtong Zhou / Ming-Wei Wang /
Abstract: Hotspot mutations in phosphoinositide 3-kinase alpha (PI3K), such as H1047R, E542K, and E545K, drive tumorigenesis across multiple cancer types. Orthosteric PI3K inhibitors are effective but have ...Hotspot mutations in phosphoinositide 3-kinase alpha (PI3K), such as H1047R, E542K, and E545K, drive tumorigenesis across multiple cancer types. Orthosteric PI3K inhibitors are effective but have toxicity against wild-type PI3K, the emergence of resistance, and a narrow therapeutic index. Allosteric inhibitors such as RLY-2608 and STX-478 offer a promising path toward mutant-specific suppression, yet the structural basis for their selectivity and mechanisms of action remain elusive. Here, we report high-resolution cryogenic electron microscopy structures of RLY-2608- and STX-478-bound H1047R, E542K, and E545K, revealing a shared cryptic allosteric pocket, accessible only through a major conformational rearrangement of the activation loop that is stabilized in oncogenic mutants. While both inhibitors occupy this pocket, they have distinct interaction networks and propagate divergent allosteric activities: RLY-2608 induces large-scale remodeling of catalytic and membrane-interacting elements, whereas STX-478 reinforces autoinhibitory interfaces between p110 and p85 subunits. Comparative analysis provides structural insights into their differentiated potency and selectivity.
History
DepositionNov 27, 2025Deposition site: PDBJ / Processing site: PDBC
Revision 1.0Sep 23, 2026Provider: repository / Type: Initial release
Revision 1.0Sep 23, 2026Data content type: EM metadata / Data content type: EM metadata / Provider: repository / Type: Initial release
Revision 1.1Oct 7, 2026Group: Data collection / Database references / Category: citation / em_admin
Item: _citation.journal_id_ISSN / _citation.journal_volume ..._citation.journal_id_ISSN / _citation.journal_volume / _citation.page_first / _citation.page_last / _citation.pdbx_database_id_PubMed / _citation.title / _em_admin.last_update
Revision 1.1Oct 7, 2026Data content type: EM metadata / Data content type: EM metadata / EM metadata / Group: Database references / Experimental summary / Data content type: EM metadata / EM metadata / Category: citation / em_admin
Data content type: EM metadata / EM metadata ...EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata
Item: _citation.journal_id_ISSN / _citation.journal_volume ..._citation.journal_id_ISSN / _citation.journal_volume / _citation.page_first / _citation.page_last / _citation.pdbx_database_id_PubMed / _citation.title / _em_admin.last_update

-
Structure visualization

Structure viewerMolecule:
MolmilJmol/JSmol

Downloads & links

-
Assembly

Deposited unit
A: Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoform
hetero molecules


Theoretical massNumber of molelcules
Total (without water)128,2242
Polymers127,8231
Non-polymers4011
Water1267
1


  • Idetical with deposited unit
  • defined by author&software
  • Evidence: electron microscopy, not applicable
TypeNameSymmetry operationNumber
identity operation1_555x,y,z1

-
Components

#1: Protein Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoform / PI3-kinase subunit alpha / PI3K-alpha / PI3Kalpha / PtdIns-3-kinase subunit alpha / ...PI3-kinase subunit alpha / PI3K-alpha / PI3Kalpha / PtdIns-3-kinase subunit alpha / Phosphatidylinositol 4 / 5-bisphosphate 3-kinase 110 kDa catalytic subunit alpha / PtdIns-3-kinase subunit p110-alpha / p110alpha / Phosphoinositide 3-kinase alpha / Phosphoinositide-3-kinase catalytic alpha polypeptide / Serine/threonine protein kinase PIK3CA


Mass: 127822.641 Da / Num. of mol.: 1
Source method: isolated from a genetically manipulated source
Source: (gene. exp.) Homo sapiens (human) / Gene: PIK3CA / Production host: Trichoplusia ni (cabbage looper)
References: UniProt: P42336, phosphatidylinositol 3-kinase, phosphatidylinositol-4,5-bisphosphate 3-kinase, non-specific serine/threonine protein kinase
#2: Chemical ChemComp-ZWE / N-(2-aminopyrimidin-5-yl)-N'-[(1R)-1-(5,7-difluoro-3-methyl-1-benzofuran-2-yl)-2,2,2-trifluoroethyl]urea


Mass: 401.291 Da / Num. of mol.: 1 / Source method: obtained synthetically / Formula: C16H12F5N5O2
#3: Water ChemComp-HOH / water


Mass: 18.015 Da / Num. of mol.: 7 / Source method: isolated from a natural source / Formula: H2O
Has ligand of interestY
Has protein modificationY

-
Experimental details

-
Experiment

ExperimentMethod: ELECTRON MICROSCOPY
EM experimentAggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction

-
Sample preparation

ComponentName: Human PI3Kalpha E542K in complex with STX-478 / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT
Source (natural)Organism: Homo sapiens (human)
Source (recombinant)Organism: Trichoplusia ni (cabbage looper)
Buffer solutionpH: 7.6
SpecimenEmbedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES
VitrificationCryogen name: ETHANE

-
Electron microscopy imaging

Experimental equipment
Model: Titan Krios / Image courtesy: FEI Company
MicroscopyModel: TFS KRIOS
Electron gunElectron source: OTHER / Accelerating voltage: 300 kV / Illumination mode: OTHER
Electron lensMode: BRIGHT FIELD / Nominal defocus max: 2000 nm / Nominal defocus min: 1000 nm
Image recordingElectron dose: 50 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k)

-
Processing

EM software
IDNameVersionCategory
1cryoSPARC4.5.1particle selection
2PHENIX1.20.1_4487model refinement
13cryoSPARC4.5.13D reconstruction
CTF correctionType: PHASE FLIPPING AND AMPLITUDE CORRECTION
3D reconstructionResolution: 2.86 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 6328286 / Symmetry type: POINT
RefinementHighest resolution: 2.86 Å
Stereochemistry target values: REAL-SPACE (WEIGHTED MAP SUM AT ATOM CENTERS)
Refine LS restraints
Refine-IDTypeDev idealNumber
ELECTRON MICROSCOPYf_bond_d0.0037178
ELECTRON MICROSCOPYf_angle_d0.6859705
ELECTRON MICROSCOPYf_dihedral_angle_d4.605927
ELECTRON MICROSCOPYf_chiral_restr0.0431055
ELECTRON MICROSCOPYf_plane_restr0.0051241

+
About Yorodumi

-
News

-
Feb 9, 2022. New format data for meta-information of EMDB entries

New format data for meta-information of EMDB entries

  • Version 3 of the EMDB header file is now the official format.
  • The previous official version 1.9 will be removed from the archive.

Related info.:EMDB header

External links:wwPDB to switch to version 3 of the EMDB data model

-
Aug 12, 2020. Covid-19 info

Covid-19 info

URL: https://pdbj.org/emnavi/covid19.php

New page: Covid-19 featured information page in EM Navigator.

Related info.:Covid-19 info / Mar 5, 2020. Novel coronavirus structure data

+
Mar 5, 2020. Novel coronavirus structure data

Novel coronavirus structure data

Related info.:Yorodumi Speices / Aug 12, 2020. Covid-19 info

External links:COVID-19 featured content - PDBj / Molecule of the Month (242)：Coronavirus Proteases

+
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)

EMDB accession codes are about to change! (news from PDBe EMDB page)

  • The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
  • The EM Navigator/Yorodumi systems omit the EMD- prefix.

Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator

External links:EMDB Accession Codes are Changing Soon! / Contact to PDBj

+
Jul 12, 2017. Major update of PDB

Major update of PDB

  • wwPDB released updated PDB data conforming to the new PDBx/mmCIF dictionary.
  • This is a major update changing the version number from 4 to 5, and with Remediation, in which all the entries are updated.
  • In this update, many items about electron microscopy experimental information are reorganized (e.g. em_software).
  • Now, EM Navigator and Yorodumi are based on the updated data.

External links:wwPDB Remediation / Enriched Model Files Conforming to OneDep Data Standards Now Available in the PDB FTP Archive

-
Yorodumi

Thousand views of thousand structures

  • Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
  • This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
  • The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.

Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi

Read more