9CZJ: PDB entry 9CZJ

Ca2+ free hSlo1 + beta2N-beta4 channel in detergent. Determined by electron microscopy at 3.54 Å resolution. Released 5 Mar 2025.

Method: Electron microscopy
Resolution: 3.54 Å
Organism: Homo sapiens
Chains: 8
Atoms: 35,325
Mol. weight: 587.19 kDa
Ligands: CLR
Released: 5 Mar 2025

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

Secondary structure: helices and β-sheets

9CZJ contains 216 α-helices and 168 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, C and D: 48 helices, 32 β-strands

Element	Residues	Length	Sheet
α-helix	23-42	20
α-helix	94-104	11
α-helix	110-134	25
α-helix	149-170	22
α-helix	175-179	5
α-helix	181-199	19
α-helix	207-216	10
α-helix	217-223	7
α-helix	230-258	29
α-helix	262-264	3
α-helix	274-285	12
α-helix	298-318	21
α-helix	319-323	5
α-helix	324-327	4
β-strand	345-349	5	1
α-helix	353-363	11
β-strand	378	1	2
α-helix	386-389	4
β-strand	401	1	2
α-helix	408-413	6
α-helix	416-418	3
β-strand	421-425	5	1
α-helix	433-450	18
β-strand	455-460	6	1
α-helix	463-465	3
α-helix	466-469	4
β-strand	482-485	4	1
α-helix	486-499	14
α-helix	503-509	7
α-helix	524-532	9
β-strand	535-540	6	3
α-helix	541-542	2
α-helix	543-545	3
α-helix	550-556	7
α-helix	557-561	5
β-strand	564-565	2	3
β-strand	567-570	4	4
β-strand	578-581	4	4
β-strand	594-599	6	3
α-helix	603-606	4
α-helix	622-624	3
β-strand	686	1	5
β-strand	687	1	6
β-strand	693	1	5
α-helix	700-702	3
β-strand	704	1	7
α-helix	707-712	6
β-strand	719-724	6	7
α-helix	730-731	2
α-helix	735-738	4
α-helix	752-753	2
β-strand	754-758	5	7
α-helix	760-765	6
α-helix	767-769	3
β-strand	776-780	5	7
α-helix	786-791	6
β-strand	799-804	6	7
α-helix	819-828	10
β-strand	831	1	8
β-strand	872	1	8
α-helix	873-875	3
β-strand	878-882	5	7
α-helix	885-890	6
α-helix	907-910	4
β-strand	914-916	3	7
α-helix	918-929	12
α-helix	932-941	10
α-helix	947-956	10
β-strand	961	1	6
α-helix	966-971	6
β-strand	976-981	6	9
α-helix	988-990	3
β-strand	994-995	2	10
α-helix	996-1007	12
β-strand	1010-1015	6	9
β-strand	1017	1	11
β-strand	1031	1	11
β-strand	1034	1	9
β-strand	1042-1043	2	10
β-strand	1048-1053	6	9

Chain B: 48 helices, 32 β-strands

Element	Residues	Length	Sheet
α-helix	23-42	20
α-helix	94-104	11
α-helix	110-134	25
α-helix	149-170	22
α-helix	175-179	5
α-helix	181-199	19
α-helix	207-216	10
α-helix	217-223	7
α-helix	230-258	29
α-helix	262-264	3
α-helix	274-285	12
α-helix	298-318	21
α-helix	319-323	5
α-helix	324-327	4
β-strand	345-349	5	12
α-helix	353-363	11
β-strand	378	1	13
α-helix	386-389	4
β-strand	401	1	13
α-helix	408-413	6
α-helix	416-418	3
β-strand	421-425	5	12
α-helix	433-450	18
β-strand	455-460	6	12
α-helix	463-465	3
α-helix	466-469	4
β-strand	482-485	4	12
α-helix	486-499	14
α-helix	503-509	7
α-helix	524-532	9
β-strand	535-540	6	14
α-helix	541-542	2
α-helix	543-545	3
α-helix	550-556	7
α-helix	557-561	5
β-strand	564-565	2	14
β-strand	567-570	4	15
β-strand	578-581	4	15
β-strand	594-599	6	14
α-helix	603-606	4
α-helix	622-624	3
β-strand	686	1	16
β-strand	687	1	17
β-strand	693	1	16
α-helix	700-702	3
β-strand	704	1	18
α-helix	707-712	6
β-strand	719-724	6	18
α-helix	730-731	2
α-helix	735-738	4
α-helix	752-753	2
β-strand	754-758	5	18
α-helix	760-765	6
α-helix	767-769	3
β-strand	776-780	5	18
α-helix	786-791	6
β-strand	799-804	6	18
α-helix	819-828	10
β-strand	831	1	19
β-strand	872	1	19
α-helix	873-875	3
β-strand	878-882	5	18
α-helix	885-890	6
α-helix	907-910	4
β-strand	914-916	3	18
α-helix	918-929	12
α-helix	932-941	10
α-helix	947-956	10
β-strand	961	1	17
α-helix	966-971	6
β-strand	976-981	6	20
α-helix	988-990	3
β-strand	994-995	2	21
α-helix	996-1006	11
β-strand	1010-1015	6	20
β-strand	1017	1	22
β-strand	1031	1	22
β-strand	1034	1	20
β-strand	1042-1043	2	21
β-strand	1048-1053	6	20

Chains E, F, G and H: 6 helices, 10 β-strands

Element	Residues	Length	Sheet
α-helix	39-41	3
α-helix	48-78	31
β-strand	79-82	4	45
β-strand	85-90	6	45
β-strand	95-99	5	46
β-strand	109-113	5	46
β-strand	115	1	47
β-strand	116-120	5	45
β-strand	127-131	5	45
α-helix	134-139	6
β-strand	145	1	47
α-helix	147-149	3
α-helix	153-168	16
β-strand	178-181	4	45
β-strand	188-190	3	45
α-helix	197-226	30

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Isoform 5 of Calcium-activated potassium channel subunit alpha-1	A, B, C, D	protein	1056	Homo sapiens	Q12791 (AlphaFold model)
Large-conductance Ca2+-activated K+ channel beta2 subunit,Calcium-activated potassium channel…	E, F, G, H	protein	239	Homo sapiens	B5BNX0 (AlphaFold model), Q86W47 (AlphaFold model)

Sequence of entity 1 (A, B, C, D), FASTA

>9CZJ_1 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

Sequence of entity 2 (E, F, G, H), FASTA

>9CZJ_2 Large-conductance Ca2+-activated K+ channel beta2 subunit,Calcium-activated potassium channel subunit beta-4 (chains E, F, G, H)
FIWTSGRTSSSYRHDEKRNIYQKIRDHDLLDKRKTVTALKAGEDKSIRLGLFLIISGVVS
LFIFGFCWLSPALQDLQATEANCTVLSVQQIGEVFECTFTCGADCRGTSQYPCVQVYVNN
SESNSRALLHSDEHQLLTNPKCSYIPPCKRENQKNLESVMNWQQYWKDEIGSQPFTCYFN
QHQRPDDVLLHRTHDEIVLLHCFLWPLVTFVVGVLIVVLTICAKSLAVKAEAMKKRKFS

Ligands and cofactors

ID	Name	Formula	Copies
CLR	Cholesterol	C27 H46 O	4

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 Q12791 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6V5A 2.0 Å, Crystal structure of the human BK channel gating ring L390P mutant
8V60 2.43 Å, F315A mutant of human Slo1 in presence of EDTA - resting VSD
11DA 2.57 Å, Human Slo1-PenitremA complex under divalent chelated condition - full model
9CZM 2.57 Å, Ca2+ bound open-inactivated hSlo1 + beta2N-beta4 channel in nanodisc.
11DC 2.58 Å, Human Slo1-PenitremA complex under divalent chelated condition - gating-ring masked out
11CZ 2.6 Å, Human Slo1-paxilline complex under divalent chelated condition - full model
8V64 2.6 Å, RCK1-RCK2 double mutant of human Slo1 in presence of EDTA - resting VSD
8GHF 2.7 Å, cryo-EM structure of hSlo1 in plasma membrane vesicles
11DB 2.71 Å, Human Slo1-Paxilline complex under divalent chelated condition - gating-ring masked
8V63 2.72 Å, R207A mutant of human Slo1 in presence of EDTA - activated VSD
9JO3 2.8 Å, Cryo-EM structure of human BKca channel-compound 10b complex
8VAZ 2.82 Å, Structure of human Slo1 and human LRRC26 in EDTA - LRRD masked

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