7XNI: Human KCNQ1-CaM in apo state

human KCNQ1-CaM in apo state. Determined by electron microscopy at 3.5 Å resolution. Released 14 Dec 2022.

Method: Electron microscopy
Resolution: 3.5 Å
Organism: Homo sapiens
Chains: 8
Atoms: 15,716
Mol. weight: 384.41 kDa
Released: 14 Dec 2022

Explore 7XNI in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

7XNI contains 108 α-helices and 8 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, D and G: 17 helices, 0 β-strands

Element	Residues	Length
α-helix	105-115	11
α-helix	120-142	23
α-helix	149-177	29
α-helix	178-180	3
α-helix	187-193	7
α-helix	197-215	19
α-helix	224-236	13
α-helix	237-241	5
α-helix	248-257	10
α-helix	259-284	26
α-helix	299-310	12
α-helix	323-361	39
α-helix	367-384	18
α-helix	390-394	5
α-helix	510-532	23
α-helix	535-536	2
α-helix	538-563	26

Chains C, E, F and H: 10 helices, 2 β-strands

Element	Residues	Length	Sheet
α-helix	7-21	15
α-helix	30-39	10
α-helix	46-53	8
α-helix	66-74	9
α-helix	80-90	11
α-helix	91-93	3
β-strand	100-102	3	1
α-helix	103-110	8
α-helix	116-118	3
α-helix	119-127	9
β-strand	136-138	3	1
α-helix	139-146	8

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Potassium voltage-gated channel subfamily KQT member 1	A, B, D, G	protein	692	Homo sapiens	P51787 (AlphaFold model)
Calmodulin-3	C, E, F, H	protein	177	Homo sapiens	P0DP25 (AlphaFold model)

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

>7XNI_1 Potassium voltage-gated channel subfamily KQT member 1 (chains A, B, D, G)
MAAASSPPRAERKRWGWGRLPGARRGSAGLAKKCPFSLELAEGGPAGGALYAPIAPGAPG
PAPPASPAAPAAPPVASDLGPRPPVSLDPRVSIYSTRRPVLARTHVQGRVYNFLERPTGW
KCFVYHFAVFLIVLVCLIFSVLSTIEQYAALATGTLFWMEIVLVVFFGTEYVVRLWSAGC
RSKYVGLWGRLRFARKPISIIDLIVVVASMVVLCVGSKGQVFATSAIRGIRFLQILRMLH
VDRQGGTWRLLGSVVFIHRQELITTLYIGFLGLIFSSYFVYLAEKDAVNESGRVEFGSYA
DALWWGVVTVTTIGYGDKVPQTWVGKTIASCFSVFAISFFALPAGILGSGFALKVQQKQR
QKHFNRQIPAAASLIQTAWRCYAAENPDSSTWKIYIRKAPRSHTLLSPSPKPKKSVVVKK
KKFKLDKDNGVTPGEKMLTVPHITCDPPEERRLDHFSVDGYDSSVRKSPTLLEVSMPHFM
RTNSFAEDLDLEGETLLTPITHISQLREHHRATIKVIRRMQYFVAKKKFQQARKPYDVRD
VIEQYSQGHLNLMVRIKELQRRLDQSIGKPSLFISVSEKSKDRGSNTIGARLNRVEDKVT
QLDQRLALITDMLHQLLSLHGGSTPGSGGPPREGGAHITQPCGSGGSVDPELFLPSNTLP
TYEQLTVPRRGPDEGSLEGGSSGGWSHPQFEK

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

>7XNI_2 Calmodulin-3 (chains C, E, F, H)
MADQLTEEQIAEFKEAFSLFDKDGDGTITTKELGTVMRSLGQNPTEAELQDMINEVDADG
NGTIDFPEFLTMMARKMKDTDSEEEIREAFRVFDKDGNGYISAAELRHVMTNLGEKLTDE
EVDEMIREADIDGDGQVNYEEFVQMMTAKLEGGSSGGLVPRGSGGSSGGHHHHHHHH

Primary citation

Structural mechanisms for the activation of human cardiac KCNQ1 channel by electro-mechanical coupling enhancers. Ma, D., Zhong, L., Yan, Z. et al. Proc Natl Acad Sci U S A (2022) 119:e2207067119-e2207067119. DOI 10.1073/pnas.2207067119 · PubMed

Other PDB entries of the same protein (UniProt P51787 (AlphaFold model), which also has an AlphaFold model), best resolution first:

3HFE 1.7 Å, A trimeric form of the Kv7.1 A domain Tail
3BJ4 2.0 Å, The KCNQ1 (Kv7.1) C-terminus, a multi-tiered scaffold for subunit assembly and protein…
7VVH 2.3 Å, Crystal Structure of the Kv7.1 C-terminal Domain in Complex with Calmodulin disease…
3HFC 2.45 Å, A trimeric form of the Kv7.1 A domain Tail, L602M/L606M mutant Semet
7XNN 2.5 Å, human KCNQ1-CaM-ML277-PIP2 complex in state B
9UJ4 2.59 Å, Structure of human KCNQ1-CaM complex
7XNK 2.6 Å, human KCNQ1-CaM in complex with ML277
7VUO 2.68 Å, Crystal Structure of the Kv7.1 C-terminal Domain in Complex with Calmodulin disease…
9VEC 2.7 Å, structure of human KCNQ1-KCNE1-CaM complex
4V0C 2.86 Å, Crystal Structure of the Kv7.1 proximal C-terminal Domain in Complex with Calmodulin
8SIK 2.9 Å, KCNQ1 with voltage sensor in the up conformation
9U7F 2.9 Å, structure of human KCNQ1-KCNE1-CaM complex

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