4L74: Ca2+-bound MthK RCK domain

Ca2+-bound MthK RCK domain at 1.9 Angstrom with single ligand. Determined by X-ray diffraction at 1.84 Å resolution. Released 23 Oct 2013.

Method: X-ray diffraction
Resolution: 1.84 Å
Organism: Methanothermobacter thermautotrophicus
Chains: 2
Atoms: 3,853
Mol. weight: 53.86 kDa
Ligands: CA
Released: 23 Oct 2013

Explore 4L74 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

4L74 contains 26 α-helices and 30 β-strands across 2 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.

Chain A: 14 helices, 16 β-strands

Element	Residues	Length	Sheet
β-strand	117-121	5	1
α-helix	125-132	8
β-strand	135	1	2
β-strand	137	1	2
β-strand	138-143	6	1
α-helix	146-148	3
α-helix	149-154	6
α-helix	157	1
β-strand	158-161	4	1
α-helix	167-172	6
β-strand	180-183	4	1
α-helix	188-201	14
β-strand	206-210	5	1
α-helix	214-216	3
α-helix	217-223	7
β-strand	227-229	3	1
α-helix	231-240	10
α-helix	247-256	10
β-strand	263-268	6	3
β-strand	273	1	4
β-strand	279	1	5
α-helix	280-283	4
α-helix	285-289	5
α-helix	291	1
β-strand	292-298	7	3
β-strand	301-304	4	3
β-strand	311	1	5
β-strand	317-322	6	3
α-helix	324-333	10
β-strand	336	1	4

Chain B: 12 helices, 14 β-strands

Element	Residues	Length	Sheet
β-strand	118-121	4	6
α-helix	125-133	9
β-strand	139-143	5	6
α-helix	146-148	3
α-helix	149-154	6
β-strand	158-161	4	6
α-helix	167-172	6
β-strand	180-183	4	6
α-helix	188-201	14
β-strand	206-210	5	6
α-helix	214-216	3
α-helix	217-223	7
β-strand	227-229	3	6
α-helix	231-241	11
α-helix	247-256	10
β-strand	263-268	6	7
β-strand	273	1	8
β-strand	279	1	9
α-helix	280-283	4
α-helix	285-289	5
β-strand	292-298	7	7
β-strand	301-303	3	7
β-strand	311	1	9
β-strand	317-322	6	7
α-helix	324-333	10
β-strand	336	1	8

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Calcium-gated potassium channel MthK	A, B	protein	242	Methanothermobacter thermautotrophicus	O27564 (AlphaFold model)

Sequence of entity 1 (A, B), FASTA

>4L74_1 Calcium-gated potassium channel MthK (chains A, B)
MGLIDVAKSRHVVICGWSESTLECLRELRGSEVFVLAEDENVRKKVLRSGANFVHGDPTR
VSDLEKANVRGARAVIVDLESDSETIHCILGIRKIDESVRIIAEAERYENIEQLRMAGAD
QVISPFVISGRLMSRSIDDGYEAMFVQDVLAEESTRRMVEVPIPEGSKLEGVSVLDADIH
DVTGVIIIGVGRGDELIIDPPRDYSFRAGDIILGIGKPEEIERLKNYISALVPRGSHHHH
HH

Ligands and cofactors

ID	Name	Formula	Copies
CA	Calcium ion	Ca	2

Primary citation

Structural basis of allosteric interactions among Ca(2+)-binding sites in a K(+) channel RCK domain. Smith, F.J., Pau, V.P., Cingolani, G. et al. Nat Commun (2013) 4:2621-2621. DOI 10.1038/ncomms3621 · PubMed

Other PDB entries of the same protein (UniProt O27564 (AlphaFold model), which also has an AlphaFold model), best resolution first:

3LDC 1.45 Å, High resolution open MthK pore structure crystallized in 100 mM K+
3LDD 1.45 Å, High resolution open MthK pore structure crystallized in 100 mM K+ and further soaked in…
6U9T 1.55 Å, Wild-type MthK pore in 50 mM K+
4HYO 1.65 Å, Crystal Structure of MthK Pore
6U9P 1.65 Å, Wild-type MthK pore in ~150 mM K+
2AEF 1.7 Å, Crystal Structures of the MthK RCK Domain in Ca2+ bound form
4HZ3 1.7 Å, MthK pore crystallized in presence of TBSb
3OUS 1.75 Å, MthK channel pore T59A mutant
3R65 1.8 Å, MthK channel pore E92Q mutant
6U9Y 1.8 Å, Wild-type MthK pore in 11 mM K+
6U9Z 1.95 Å, Wild-type MthK pore in 6 mM K+
2AEJ 2.1 Å, Crystal Structures of the MthK RCK Domain in no Ca2+ bound form

Browse structure collections

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