2026-06-17RELPDBeINITIAL_RELEASEREPOSITORYINITIAL_RELEASEREPOSITORYINITIAL_RELEASEREPOSITORYINITIAL_RELEASEREPOSITORYINITIAL_RELEASEREPOSITORYINITIAL_RELEASEREPOSITORYINITIAL_RELEASEREPOSITORYPDBePDBe2026-03-192026-05-272026-05-272026-06-17Cancer Research UKDRCRPG-May23/100002United KingdomCancer Research UKC20724/A26752United KingdomWellcome Trust218482/Z/19/ZUnited KingdomWellcome Trust060208/Z/00/ZUnited KingdomWellcome Trust093305/Z/10/ZUnited KingdomFocused refinement of the helix-stabilized MEGF8-MOSMO complex with nanobody 270Williams CCarrique LPardon ENocka LMHedger GPusapati GVParashara PLatorraca NRSarkar PLartey DGao LMilenkovic LChalk RSteyaert JBazan FRouse SLMarqusee SKong JHRohatgi RSiebold CE3 Ubiquitin Ligase, Hedgehog Signaling, Single-pass Membrane Protein, Membrane Protein Complex, Smoothened, Tetraspanin, Cell Surface Receptor, Primary Cilium, Morphogen, Signal Transduction, Human, Carpenter Syndrome, Cancer, Nanobody, Palmitoylation, GDN, MEMBRANE PROTEINWilliams CNocka LMHedger GParashara PPardon ELatorraca NRPusapati GVSarkar PLartey DGao LMilenkovic LChalk RSteyaert JMarqusee SCarrique LBazan JFRouse SLKong JHSiebold CRohatgi RDesign principles of a membrane-spanning ubiquitin ligase.Mol.CellUS8622072222.e16202642190653doi:10.1016/j.molcel.2026.05.0011097-27652168MOCEFLEMD-53328focused EM volumeEMD-53327consensus EM volumeEMD-53329other EM volumeComposite map.EMDBEMD-53328focused EM volumeEMDBEMD-53327consensus EM volumeEMDBEMD-53329other EM volumeComposite map.EMDBEMD-57249associated EM volumePDB9QS6unspecifiedComposite model of the helix-stabilised MMM complex bound to nanobody 270.Helix-stabilized human MEGF8-MOSMO binary complex bound to nanobody 270Helix-stabilized human MEGF8-MOSMO binary complex bound to nanobody 2700234MMM complex was obtained by co-expression of MEGF8, MOSMO and MGRN1 components in HEK293S GnTI- TetR cells. The MMM complex was purified by tandem affinity purification. Purified nanobody 270, from E. coli WK6 cells, was added to MMM complex and the MMM-nanobody 270 complex formed on size-exclusion chromatography. A focused refinement of extracellular and transmembrane regions of the MMM complex was performed to obtain this MEGF8-MOSMO map.Homo sapiensMOSMO12Ternary complex with MEGF8 and MGRN1 was obtained by co-expressing helix-stabilized MEGF8, MOSMO and MGRN1 to form the MMM complex.Homo sapiensHelix-stabilized MEGF814Cytoplasmic helix of MEGF8 (residues 2605-2624) were replaced with E/RK repeats (EEEEKKKREEEERRRREEEK). MEGF8 was co-expressed with MOSMO and MGRN1, then the complex was purified on size-exclusion chromatography with nanobody 270.Homo sapiensNanobody 27012Lama glamaModulator of smoothened proteinHomo sapiensHuman MOSMO with C-terminal 3C protease site-TwinStrep tags.Homo sapiensLEVOMDKLTIISGCLFLAADIFAIASIANPDWINTGESAGALTVGLVRQCQTIHGRDRTCIPPRLPPEWVTTLFFIIMGIISLT
VTCGLLVASHWRREATKYARWIAFTGMILFCMAALIFPIGFYINEVGGQPYKLPNNTVVGSSYVLFVLSIFFTIVGLLFA
GKVCLPGGTLEVLFQGPGGSGSAWSHPQFEKGGGSGGGSGGSAWSHPQFEKQ8NHV5Nanobody 270Lama glamaNanobody 270 with C-terminal His6-EPEA tags.Escherichia coli K-12LEVOQVQLVESGGGLVQAGGSLRLSCAASGSIFSYDDMGWYRQAPGKQRELVATFTNVGSTNYVDSVKGRFTISRDNAKNTVYL
QMNSLKPEDTAVYYCHAYTVRRFQGMEYWGKGTQVTVSSHHHHHHEPEAIsoform 2 of Multiple epidermal growth factor-like domains protein 8Homo sapiensCytoplasmic helix of human MEGF8 (residues 2605-2624) were replaced with E/RK repeats (EEEEKKKREEEERRRREEEK). Human MEGF8 has a C-terminal 1D4 tag.Homo sapiensLEVOKCQCNGHADTCNEQDGTGCPCQNNTETGTCQGSSPSDRRDCYKYQCAKCRESFHGSPLGGQQCYRLISVEQECCLDPTSQ
TNCFHEPKRRALGPGRTVLFGVQPKFTNVDIRLTLDVTFGAVDLYVSTSYDTFVVRVAPDTGVHTVHIQPPPAPPPPPPP
ADGGPRGAGDPGGAGASSGPGAPAEPRVREVWPRGLITYVTVTEPSAVLVVRGVRDRLVITYPHEHHALKSSRFYLLLLG
VGDPSGPGANGSADSQGLLFFRQDQAHIDLFVFFSVFFSCFFLFLSLCVLLWKEEEEKKKREEEERRRREEEKMASRPFA
KVTVCFPPDPTAPASAWKPAGLPPPAFRRSEPFLAPLLLTGAGGPWGPMGGGCCPPAIPATTAGLRAGPITLEPTEDGMA
GVATLLLQLPGGPHAPNGACLGSALVTLRHRLHEYCGGGGGAGGSGHGTGAGRKGLLSQDNLTSMSLGTETSQVAPAQ7Z7M0-2singleParticleparticle57.5150.0NaClsodium chloride20.0C8H19NO4SHEPES2.0C3H8O3glycerol2.0CaCl2calcium chloride0.02C19H36O10glycyl-dodecyl-beta-D-maltoside (GDN)20 mM HEPES pH 7.5, 150 mM NaCl, 2% (v/v) glycerol, 2 mM CaCl2, 0.02% (w/v) GDNQuantifoil R1.2/1.3COPPER300CARBONHOLEYETHANE100278FEI VITROBOT MARK IVTFS KRIOSFLOOD BEAMBRIGHT FIELDFIELD EMISSION GUN30050.02.71.62.6165000.0FEI TITAN KRIOS AUTOGRID HOLDERNITROGENTFS Selectris X10TFS FALCON 4i (4k x 4k)1159953.0750.0Images were collected in counted mode.13362125Particles initially picked from 2D templates (imported from EMD-53323 dataset).Patch CTF estimation was performed in cryoSPARC live pre-processing.PHASE FLIPPING AND AMPLITUDE CORRECTION9QQSFor helix-stabilized MEGF8-MOSMO-nanobody 270 sub-complex, wild-type MEGF8-MOSMO-nanobody 270 (9QQS PDB) was docked in the map using fit-in-map tool in ChimeraX. Mutated residues in the MEGF8 cytoplasmic helix were manually changed in Coot.1C12.95FSC 0.143 CUT-OFFcryoSPARCLocal refinement.Particle subtraction of the detergent micelle and cytoplasmic regions (MEGF8 ICD-MGRN1) was performed before local refinement of the MEGF8 (residues 2374-2614)-MOSMO-nanobody 270 complex.120547MAXIMUM LIKELIHOODMAXIMUM LIKELIHOOD3109042.03D classification (without alignment) was performed in cryoSPARC using a mask around transmembrane and extracellular regions of the map (i.e. MOSMO, MEGF8 residues 2374-2580, nanobody 270).9QS6PDBexperimental modelRIGID BODY FITInitial local fitting was done using ChimeraX then manual model building in Coot was interspersed with real space refinement in Phenix.REAL98.299999999999997emd_57249_msk_1.mapemd_57249_half_map_1.map.gz1IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
480
480480
0
00480480480350.544350.544350.54490.090.090.0XYZ-0.640359640.7628235-0.000093799960.0730821340.73030.73030.7303AUTHORemd_57249_half_map_2.map.gz1IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)