2026-09-09 REL RCSB INITIAL_RELEASE REPOSITORY INITIAL_RELEASE REPOSITORY RCSB RCSB 2025-08-30 2026-09-09 2026-09-09 2026-09-09 Cystic Fibrosis Foundation HUNT13XX0, HUNT18G0, HUNT20G0, 004400G222-Hunt, 007997G224-Hunt, FRANK16XX0, FRANK18G0 United States Alternative NBD1-binding geometry in channel-formed, ATP-bound, VX809-bound, T2a-nanobody-bound wild-type human CFTR (Composite map from PHENIX) Hunt JF Paige AS Govaerts C Goldberg PM Wang C Loughlin BJ Kappes JC Yang Z Jiang F Govaerts C Overtus M Rich Z cystic fibrosis, CFTR, nanobody, protein folding, MEMBRANE PROTEIN Hunt FJ Paige AS Cohen BM Goldberg PM Wang C Loughlin BJ Kappes JC Yang Z Jiang F Govaerts C Overtus M Urbatsch IL Lukacs G Nanobody-Driven Stabilization Synergistically Rescues F508del-CFTR and Reveals an Alternative Active State of the Channel To Be Published 0353 EMD-71756 consensus EM volume
Consensus
 EMD-71757 focused EM volume
AHD1
 EMD-71758 focused EM volume
AHD2
 EMD-71759 focused EM volume
CORE1
 EMD-71760 focused EM volume
CORE2
 EMD-71761 focused EM volume
WalkerB1
 EMD-71762 focused EM volume
WalkerB2
 EMD-71763 focused EM volume
NBD1+T2a
 EMD-71764 focused EM volume
NBD2
 EMD-71765 focused EM volume
T2a
 9y1q FULLOVERLAP EMDB EMD-71756 consensus EM volume
Consensus
 EMDB EMD-71757 focused EM volume
AHD1
 EMDB EMD-71758 focused EM volume
AHD2
 EMDB EMD-71759 focused EM volume
CORE1
 EMDB EMD-71760 focused EM volume
CORE2
 EMDB EMD-71761 focused EM volume
WalkerB1
 EMDB EMD-71762 focused EM volume
WalkerB2
 EMDB EMD-71763 focused EM volume
NBD1+T2a
 EMDB EMD-71764 focused EM volume
NBD2
 EMDB EMD-71765 focused EM volume
T2a
 EMDB EMD-72403 associated EM volume
Alternative NBD1-binding geometry in channel-formed, ATP-bound, VX809-bound, T2a-nanobody-bound wild-type human CFTR (Composite map from PHENIX)
 Wild-type human CFTR solubilized in digitonin and cholesterol-hemisuccinate plus T2a nanobody in the presence of 2 mM MgATP Wild-type human CFTR solubilized in digitonin and cholesterol-hemisuccinate plus T2a nanobody in the presence of 2 mM MgATP 0 1 2 3 Homo sapiens 0.1725 Wild type human Cystic Fibrosis Transmembrane Conductance Regulator (hCFTR) 1 1 Homo sapiens T2a nanobody 2 2 Lama glama Cystic fibrosis transmembrane conductance regulator Homo sapiens 0.17273498399999998 1 Cricetulus griseus LEVO MQRSPLEKASVVSKLFFSWTRPILRKGYRQRLELSDIYQIPSVDSADNLSEKLEREWDRELASKKNPKLINALRRCFFWR FMFYGIFLYLGEVTKAVQPLLLGRIIASYDPDNKEERSIAIYLGIGLCLLFIVRTLLLHPAIFGLHHIGMQMRIAMFSLI YKKTLKLSSRVLDKISIGQLVSLLSNNLNKFDEGLALAHFVWIAPLQVALLMGLIWELLQASAFCGLGFLIVLALFQAGL GRMMMKYRDQRAGKISERLVITSEMIENIQSVKAYCWEEAMEKMIENLRQTELKLTRKAAYVRYFNSSAFFFSGFFVVFL SVLPYALIKGIILRKIFTTISFCIVLRMAVTRQFPWAVQTWYDSLGAINKIQDFLQKQEYKTLEYNLTTTEVVMENVTAF WEEGFGELFEKAKQNNNNRKTSNGDDSLFFSNFSLLGTPVLKDINFKIERGQLLAVAGSTGAGKTSLLMMIMGELEPSEG KIKHSGRISFCSQFSWIMPGTIKENIIFGVSYDEYRYRSVIKACQLEEDISKFAEKDNIVLGEGGITLSGGQRARISLAR AVYKDADLYLLDSPFGYLDVLTEKEIFESCVCKLMANKTRILVTSKMEHLKKADKILILHEGSSYFYGTFSELQNLQPDF SSKLMGCDSFDQFSAERRNSILTETLHRFSLEGDAPVSWTETKKQSFKQTGEFGEKRKNSILNPINSIRKFSIVQKTPLQ MNGIEEDSDEPLERRLSLVPDSEQGEAILPRISVISTGPTLQARRRQSVLNLMTHSVNQGQNIHRKTTASTRKVSLAPQA NLTELDIYSRRLSQETGLEISEEINEEDLKECFFDDMESIPAVTTWNTYLRYITVHKSLIFVLIWCLVIFLAEVAASLVV LWLLGNTPLQDKGNSTHSRNNSYAVIITSTSSYYVFYIYVGVADTLLAMGFFRGLPLVHTLITVSKILHHKMLHSVLQAP MSTLNTLKAGGILNRFSKDIAILDDLLPLTIFDFIQLLLIVIGAIAVVAVLQPYIFVATVPVIVAFIMLRAYFLQTSQQL KQLESEGRSPIFTHLVTSLKGLWTLRAFGRQPYFETLFHKALNLHTANWFLYLSTLRWFQMRIEMIFVIFFIAVTFISIL TTGEGEGRVGIILTLAMNIMSTLQWAVNSSIDVDSLMRSVSRVFKFIDMPTEGKPTKSTKPYKNGQLSKVMIIENSHVKK DDIWPSGGQMTVKDLTAKYTEGGNAILENISFSISPGQRVGLLGRTGSGKSTLLSAFLRLLNTEGEIQIDGVSWDSITLQ QWRKAFGVIPQKVFIFSGTFRKNLDPYEQWSDQEIWKVADEVGLRSVIEQFPGKLDFVLVDGGCVLSHGHKQLMCLARSV LSKAKILLLDEPSAHLDPVTYQIIRRTLKQAFADCTVILCEHRIEAMLECQQFLVIEENKVRQYDSIQKLLNERSLFRQA ISPSDRVKLFPHRNSSKCKSKPQIAALKEETEEEVQDTRLLEENLYFQGGGGSGGSWSHPQFEKAAAGGGSGGGSWSHPQ FEK P13569 5.6.1.6 T2a nanobody Lama glama 0.015820306 1 Escherichia coli LEVO QVQLQESGGGLVQAGGSLRLSCAASGSIFRIDAMGWYRQAPGKQRELVAHSTSGGSTDYADSVKGRFTISRDNAKNTVYL QMNSLKPEDTAVYYCNADVRTRWYASNNYWGQGTQVTVSSAAAHHHHHHGAAEQKLISEEDLNGAA UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK-UNK Homo sapiens 0.0014647969999999999 1 Cricetulus griseus LEVO (UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK)(UNK) (UNK) Digitonin 0.0012293119999999998 1 AJP CHOLESTEROL 0.000386654 4 CLR O-[(R)-{[(2R)-2,3-bis(octadecanoyloxy)propyl]oxy}(hydroxy)phosphoryl]-L-serine 0.000792075 2 P5S 1,2-DIACYL-SN-GLYCERO-3-PHOSPHOCHOLINE 0.0007901449999999999 2 PC1 1,2-DIACYL-GLYCEROL-3-SN-PHOSPHATE 0.000704998 3 3PH PHOSPHATIDYLETHANOLAMINE 0.0007340389999999999 2 PTY PALMITIC ACID 0.00025642399999999994 4 PLM MYRISTIC ACID 0.000228371 1 MYR DODECANE 0.000170335 3 D12 DECANE 0.000142282 1 D10 HEXANE 8.6175e-05 3 HEX N-OCTANE 0.000114229 1 OCT ADENOSINE-5'-TRIPHOSPHATE 0.000507181 2 ATP MAGNESIUM ION 2.4305e-05 2 MG Lumacaftor 0.00045240699999999994 1 VX8 singleParticle particle 1.5 7.5 200.0 NaCl Sodium Chloride 3.0 MgCl2 Magnesium Chloride 50.0 C4H11NO3 Tris buffer 0.06 C56H92O29 Digitonin 2.0 C10H16N5O13P3 ATP Quantifoil R0.6/1 GOLD 300 GOLD HOLEY 50.0 PLASMA CLEANING OTHER
The grid was treated in a Solarus Plasma Cleaner 950 (Gatan Inc., USA) for 25 sec with O2/H2 flow-rates of 27.5/6.4 sccm and 15 W cleaning power.
 ETHANE 100 277 FEI VITROBOT MARK IV TFS KRIOS FLOOD BEAM BRIGHT FIELD FIELD EMISSION GUN 300 100.0 2.7 0.2 2.9 105000.0 FEI TITAN KRIOS AUTOGRID HOLDER NITROGEN 85.0 90.0 GIF Quantum ER 20 GATAN K3 BIOQUANTUM (6k x 4k) 5760 4092 1 11110 2.5 58.0
Movies comprised 40 frames collected in 2.5 seconds.
 1 2635244 cryoSPARC 4.3.1 Patch CTF correction PHASE FLIPPING AND AMPLITUDE CORRECTION 1 BACK PROJECTION 3.86 FSC 0.143 CUT-OFF cryoSPARC 4.7.0 36856 MAXIMUM LIKELIHOOD cryoSPARC 4.3.1 MAXIMUM LIKELIHOOD cryoSPARC 4.3.1 5 73709.0 cryoSPARC 4.7.0
373422 particles assigned to 16 protein classes at the end of iterative heteroclassifications including 6 decoy volumes.
 emd_72403.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 320 320 320 0 0 0 320 320 320 265.6 265.6 265.6 90.0 90.0 90.0 X Y Z -27.015620999999999 48.351469999999999 0.00020139494 0.956961 0.83000004 0.83000004 0.83000004 9.5 AUTHOR
Real space refinement in PHENIX using default parameters with separate grouped ADPs for side chain and backbone atoms. REMARK Because of the relatively low resolution and the anisotropy of the map corresponding to this model, it was built primarily by transferring coordinates from higher resolution structures with equivalent conformations. The model for NBD2, the transmembrane region, and the bound lipids came from a 2.98 A structure of an "NBD1less" conformation of human CFTR that has no significant density for NBD1. The model for NBD1 and T2a came from a 3.04 A structure of the standard "VShaped" conformation of human CFTR (without the internal chloride channel formed) that has the T2a nanobody bound to NBD1. The relevant portions of those two models were aligned with the density in ChimeraX and then combined with a model for the C peptide that was built directly into this map. The C peptide, which has not been assigned to a specific CFTR sequence, likely derives from either the Regulatory Insertion spanning residues 403-436 or the R Region spanning residues 638-840. No manual rebuilding was performed on the model, although a small number of protein segments and two ligands showing stereochemical strains or clashes in an initial refinement in PHENIX were subject to real space refinement in COOT. Occupancy refinement was performed on the two backbone segments that have alternative conformations in the NBD1less model (541-548 and 919-922) and also on residues 1012-1034 in CFTR and the entirety of the T2a nanobody.
 emd_72403_half_map_1.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 320 320 320 0 0 0 320 320 320 265.6 265.6 265.6 90.0 90.0 90.0 X Y Z -6.6942663 15.921805000000001 0.00094897463 0.72320396 0.83000004 0.83000004 0.83000004 AUTHOR emd_72403_half_map_2.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 320 320 320 0 0 0 320 320 320 265.6 265.6 265.6 90.0 90.0 90.0 X Y Z -7.1013556 15.467611 0.00069120387 0.7210142 0.83000004 0.83000004 0.83000004 AUTHOR