9CZM: PDB entry 9CZM

Ca2+ bound open-inactivated hSlo1 + beta2N-beta4 channel in nanodisc. Determined by electron microscopy at 2.57 Å resolution. Released 5 Mar 2025.

Method
Electron microscopy
Resolution
2.57 Å
Organism
Homo sapiens
Chains
8
Atoms
36,052
Mol. weight
613.6 kDa
Ligands
POV, MG, CA, CLR
Released
5 Mar 2025

Explore 9CZM in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9CZM contains 209 α-helices and 156 β-strands across 8 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chains A, B, C and D: 46 helices, 33 β-strands

ElementResiduesLengthSheet
α-helix22-5332
α-helix93-10513
α-helix110-13324
β-strand139-14137
α-helix148-17023
α-helix174-1785
α-helix181-1877
α-helix191-1999
β-strand201-20337
α-helix206-21611
α-helix217-2237
α-helix230-25829
α-helix274-28512
α-helix298-32427
β-strand33918
β-strand34218
β-strand344-34969
α-helix353-36311
β-strand374-37969
α-helix382-3843
α-helix385-3928
β-strand398-40259
α-helix408-4136
α-helix416-4183
β-strand421-42559
α-helix433-45018
β-strand456-46059
α-helix463-4697
α-helix477-4793
β-strand482-48549
α-helix486-49914
α-helix503-5119
α-helix524-5329
β-strand535-540610
α-helix550-55910
β-strand564110
β-strand568111
β-strand581111
β-strand594-599610
α-helix602-6054
α-helix606-6083
β-strand686-687212
β-strand692113
β-strand693112
α-helix700-7034
β-strand704114
α-helix707-7126
β-strand718-724714
α-helix730-7312
α-helix735-7384
α-helix740-7423
β-strand743113
β-strand754-758514
α-helix760-77011
β-strand776-780514
α-helix786-7916
α-helix794-7963
β-strand797-804814
α-helix818-82912
β-strand878-881414
α-helix885-8906
α-helix903-9053
α-helix907-9104
β-strand914-915214
α-helix917-9215
α-helix922-9298
α-helix933-94210
α-helix947-95610
α-helix959-9602
β-strand961-962212
α-helix966-9705
β-strand976-981615
α-helix988-9936
β-strand995116
β-strand1011-1017715
β-strand1031-1035515
β-strand1042116
β-strand1047-1053715
α-helix1054-10552
Chains E, F and H: 6 helices, 6 β-strands
ElementResiduesLengthSheet
α-helix41-7737
β-strand80-8451
β-strand85-99152
β-strand109-120122
β-strand128-13032
α-helix134-1396
α-helix153-16917
α-helix1731
α-helix1751
β-strand176-18161
β-strand185-19061
α-helix197-23438
Chain G: 7 helices, 6 β-strands
ElementResiduesLengthSheet
α-helix3-53
α-helix41-7737
β-strand80-84547
β-strand85-991548
β-strand109-1201248
β-strand128-130348
α-helix134-1396
α-helix153-16917
α-helix1731
α-helix1751
β-strand176-181647
β-strand185-190647
α-helix197-23438

Molecules and chains

MoleculeChainsTypeLengthOrganismUniProt
Large-conductance Ca2+-activated K+ channel beta2 subunit,Calcium-activated potassium channel…E, F, G, Hprotein239Homo sapiensB5BNX0 (AlphaFold model), Q86W47 (AlphaFold model)
Isoform 5 of Calcium-activated potassium channel subunit alpha-1A, B, C, Dprotein1056Homo sapiensQ12791 (AlphaFold model)
Sequence of entity 1 (E, F, G, H), FASTA
>9CZM_1 Large-conductance Ca2+-activated K+ channel beta2 subunit,Calcium-activated potassium channel subunit beta-4 (chains E, F, G, H)
FIWTSGRTSSSYRHDEKRNIYQKIRDHDLLDKRKTVTALKAGEDKSIRLGLFLIISGVVS
LFIFGFCWLSPALQDLQATEANCTVLSVQQIGEVFECTFTCGADCRGTSQYPCVQVYVNN
SESNSRALLHSDEHQLLTNPKCSYIPPCKRENQKNLESVMNWQQYWKDEIGSQPFTCYFN
QHQRPDDVLLHRTHDEIVLLHCFLWPLVTFVVGVLIVVLTICAKSLAVKAEAMKKRKFS
Sequence of entity 2 (A, B, C, D), FASTA
>9CZM_2 Isoform 5 of Calcium-activated potassium channel subunit alpha-1 (chains A, B, C, D)
MDALIIPVTMEVPCDSRGQRMWWAFLASSMVTFFGGLFIILLWRTLKYLWTVCCHCGGKT
KEAQKINNGSSQADGTLKPVDEKEEAVAAEVGWMTSVKDWAGVMISAQTLTGRVLVVLVF
ALSIGALVIYFIDSSNPIESCQNFYKDFTLQIDMAFNVFFLLYFGLRFIAANDKLWFWLE
VNSVVDFFTVPPVFVSVYLNRSWLGLRFLRALRLIQFSEILQFLNILKTSNSIKLVNLLS
IFISTWLTAAGFIHLVENSGDPWENFQNNQALTYWECVYLLMVTMSTVGYGDVYAKTTLG
RLFMVFFILGGLAMFASYVPEIIELIGNRKKYGGSYSAVSGRKHIVVCGHITLESVSNFL
KDFLHKDRDDVNVEIVFLHNISPNLELEALFKRHFTQVEFYQGSVLNPHDLARVKIESAD
ACLILANKYCADPDAEDASNIMRVISIKNYHPKIRIITQMLQYHNKAHLLNIPSWNWKEG
DDAICLAELKLGFIAQSCLAQGLSTMLANLFSMRSFIKIEEDTWQKYYLEGVSNEMYTEY
LSSAFVGLSFPTVCELCFVKLKLLMIAIEYKSANRESRILINPGNHLKIQEGTLGFFIAS
DAKEVKRAFFYCKACHDDITDPKRIKKCGCKRLEDEQPSTLSPKKKQRNGGMRNSPNTSP
KLMRHDPLLIPGNDQIDNMDSNVKKYDSTGMFHWCAPKEIEKVILTRSEAAMTVLSGHVV
VCIFGDVSSALIGLRNLVMPLRASNFHYHELKHIVFVGSIEYLKREWETLHNFPKVSILP
GTPLSRADLRAVNINLCDMCVILSANQNNIDDTSLQDKECILASLNIKSMQFDDSIGVLQ
ANSQGFTPPGMDRSSPDNSPVHGMLRQPSITTGVNIPIITELVNDTNVQFLDQDDDDDPD
TELYLTQPFACGTAFAVSVLDSLMSATYFNDNILTLIRTLVTGGATPELEALIAEENALR
GGYSTPQTLANRDRCRVAQLALLDGPFADLGDGGCYGDLFCKALKTYNMLCFGIYRLRDA
HLSTPSQCTKRYVITNPPYEFELVPTDLIFCLMQFD

Ligands and cofactors

IDNameFormulaCopies
POV(2S)-3-(hexadecanoyloxy)-2-[(9Z)-octadec-9-enoyloxy]propyl…C42 H82 N O8 P32
MGMagnesium ionMg4
CACalcium ionCa8
CLRCholesterolC27 H46 O8

Water and common crystallization additives (K) are not listed.

Primary citation

Ball-and-chain inactivation of a human large conductance calcium-activated potassium channel. Agarwal, S., Kim, E.D., Lee, S. et al. Nat Commun (2025) 16:1769-1769. DOI 10.1038/s41467-025-56844-4 · PubMed

Other PDB entries of the same protein (UniProt B5BNX0 (AlphaFold model), which also has an AlphaFold model), best resolution first:

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