CODSWALLOP

Calmodulin-1

Homo sapiens · seed P0DP23 · 149 aa · family defined as ≥30% identity to that seed · compiled 07 October 2026

CATH and SCOP identifiers come from the RCSB's own structure annotations, which the Domains panel already reads, so these are looked up rather than guessed at.

1,113Entries 1,216Entities 448Constructs 78Organisms 469Ligand-bound
1.00 ÅBest res.
2.71 ÅMedian res.

Every figure here is counted over the whole family rather than quoted from one entry.

The reference structure

9NVO, the structure every other member of this family is superposed onto. Rendered by the RCSB and embedded here: the live app shows an interactive viewport, which a document that fetches nothing cannot.

Rendered structure of 9NVO
9NVO at the RCSB · open it in the 3D viewer

Which residues anyone has ever seen

How many of this family's constructs contain each residue of the seed. A trough is a stretch nobody has put in a construct, which is a construct-design answer rather than a disorder one.

1741491140 constructs

Constructs, most-used first

448 distinct constructs across 1,113 entries. 656 polymer entities differ from the UniProt canonical sequence in some way, 50 carry a recognised expression tag and 36 carry a fusion partner.

"Differs from canonical" is not the same as "engineered". The canonical sequence is the full gene product, so a secreted protein whose structures all start after its signal peptide counts every one of them as different: lysozyme's most-used construct, residues 19–147 on 1,239 entities, is simply the mature protein. Read the construct column below for what was actually done, rather than this count.

EntitiesLengthBest (Å)Best entryWhat was made
164 149 1.24 7BF1 matches the canonical sequence
91 148 1.08 2O5G residues 2-149
29 151 2.00 1W7J residues 58-208; V58M
28 484 1.88 3NYV residues 27-507; 3-residue insertion after 29
20 161 4.90 9MOW matches the canonical sequence
14 161 4.63 9YAQ matches the canonical sequence
14 177 2.50 7XNN His8; Thrombin site
12 89 1.37 3SD6 residues 1-89
11 145 70.00 1M8Q residues 21-165; Q23E, Q25E, Q27E +6 more
11 147 70.00 1M8Q residues 4-150; P5K, D6A, E7A +6 more
11 149 2.20 2X51 matches the canonical sequence
11 156 2.00 1WDC residues 2-157
10 156 2.00 1WDC residues 2-157
10 492 1.84 9NTZ residues 52-538; 5-residue insertion after 54; G54S, E55H, R56H +11 more
9 146 2.77 9ZRQ residues 3-148
9 170 1.70 4F0Z matches the canonical sequence
9 172 2.35 2GGM matches the canonical sequence
9 188 3.00 9YP9 matches the canonical sequence
8 164 2.61 8FMO C35S, C84S, D115E
7 148 2.70 9CFV residues 1-148
7 149 3.58 8Y40 E32A, E68A, E105A +1 more
7 160 4.80 6KN8 residues 2-161; E115D
7 169 3.00 9YP9 matches the canonical sequence
6 90 1.75 1AVS residues 2-91
6 129 residues 53-180; 2 internal deletions; 9-residue insertion after 98; L53G, L54D, Q55D +60 more

Showing the 25 most-used of 448.

Positions people deliberately mutate

Columns where the wild-type residue still dominates but a real minority carries something else, which is a different question from "what varies across species".

P67E 50% Q136R 50% S18D 49% Q144K 48% A2V 48% N54D 48% T27K 47% D51E 47% K149V 47% T147K 47% M110L 47% A148G 46% T35D 46% A103G 46% A58E 45% A11N 45% R127K 44% I131K 44% S39M 44% T29D 44% T80D 44% D3E 44% N112T 43% A74V 43% Y100K 42% K22L 42% I86L 42% R87L 42% M1A 41% T71V 40%

What it assembles into

Oligomeric stateChainsEntriesShare
monomeric1 347 31.2%
dimeric2 292 26.2%
trimeric3 113 10.2%
octameric8 89 8.0%
tetrameric4 54 4.9%
hexameric6 43 3.9%
dodecameric12 42 3.8%
pentameric5 21 1.9%

523 entries have the depositor's assembly corroborated by PISA, 568 carry the depositor's word alone and 22 were assigned by PISA where the depositor gave none. The middle figure is not a disagreement: PISA may have returned nothing or never run. 40 entries carry more than one assembly with different chain counts, so they have no single answer to quote: 1CM1, 1IWQ, 1K90, 1M46, 1NIW, 1PK0, 1QX2, 1QX7, 1XFW, 1YTZ, 1YV0, 1ZUZ, 2AAO, 2BE6, 2F2O, 2F2P, 2NXQ, 2PQ3, 3B32, 3BXL.

Domain architecture

Every source's own domains on the seed axis, one row each. They are not merged: Pfam, CATH, SCOP and InterPro disagree about boundaries, and a merged track would state a consensus none of them gave.

CATHEF-handGreen fluorescent proteinPhosphorylase Kinase; domaSCOP2BEF-handEF-handEF-handEF-handEF-handEF-handEF-handMyosin s1 fragment, N-termEF-handProtein kinase-like (PK-liProtein kinase-like (PK-liEF-handP-loop motor domain174149
DomainSourceSpan (seed)Chains
EF-handCATH 1.10.238.10 15–117 553
Green fluorescent proteinCATH 2.40.155.10 40–149 36
Phosphorylase Kinase; domain 1CATH 3.30.200.20 61–149 101
EF-handSCOP2B 8032568 4–148 26
EF-handSCOP2B 8093724 4–149 21
EF-handSCOP2B 8104309 4–149 18
EF-handSCOP2B 8039032 4–147 13
EF-handSCOP2B 8034158 5–148 14
EF-handSCOP2B 8033359 6–149 16
EF-handSCOP2B 8062903 7–149 12
Myosin s1 fragment, N-terminal domainSCOP2B 8032925 8–65 13
EF-handSCOP2B 8037367 9–149 17

What binds it

ADP ADP131 entries ATP ATP32 entries ANP ANP20 entries CFF CFF18 entries NAG NAG16 entries GTP GTP14 entries GDP GDP14 entries FK5 FK511 entries SF4 SF48 entries FAD FAD8 entries AMP AMP7 entries TFP TFP6 entries
ComponentClassNameEntriesBest (Å)
CAion Calcium Ion 664 1.00
MGion Magnesium Ion 180 1.45
ADPcofactor Adenosine-5'-Diphosphate 131 1.96
ZNion Zinc Ion 93 1.30
SO4ion Sulfate Ion 63 1.08
GOLcryoprotectant Glycerol 44 1.15
PO4ion Phosphate Ion 44 1.80
Kion Potassium Ion 43 2.50
ATPcofactor Adenosine-5'-Triphosphate 32 2.22
EDOcryoprotectant 1,2-Ethanediol 25 1.65
FEion Fe (Iii) Ion 23 1.85
ANPcofactor Phosphoaminophosphonic Acid-Adenylate Ester 20 1.70
CLion Chloride Ion 20 1.55
CFFligand Caffeine 18 2.37
ACTcryoprotectant Acetate Ion 17 1.15
NAGcofactor 2-Acetamido-2-Deoxy-Beta-D-Glucopyranose 16 2.60
NAion Sodium Ion 15 1.65
GTPcofactor Guanosine-5'-Triphosphate 14 3.10
GDPcofactor Guanosine-5'-Diphosphate 14 3.10
PIObuffer [(2r)-2-Octanoyloxy-3-[Oxidanyl-[(1r,2r,3s,4r,5r,6s)-2,3,6-Tris( 13 2.50

How it crystallises

Parsed from the free text 501 depositors typed into _exptl_crystal_grow.pdbx_details, out of 508 entries that recorded anything at all. Median pH 7.0 (range 3.3 to 10.3).

Precipitants

PEG × Calcium chloride × Ammonium sulfate × Magnesium chloride × Sodium chloride × MPD × Sodium citrate × Lithium sulfate × Isopropanol × Tacsimate × Sodium malonate × Sodium formate × PEG (unspecified) × Ethanol ×

Buffers

HEPES × Citrate × Sodium acetate × Tris × Bis-Tris × MES × Sodium cacodylate × Bis-Tris propane × Phosphate × Glycine × Imidazole × CHES × CAPS ×

Which entries to trust

1,094 entries carry a wwPDB validation report: 418 clean, 318 worth a check and 358 with something to explain. Median clashscore 8.66, median RSRZ outliers 4.73%, median R-free minus R-work 0.042. 1,044 have released structure factors.

Across species

OrganismEntriesBest (Å)Ligand-boundSeed covered
Homo sapiens535 1.17 224 100%
Gallus gallus81 1.08 11 100%
Mus musculus66 1.72 48 100%
Toxoplasma gondii48 1.80 41 100%
Rattus norvegicus44 1.30 15 100%
Bos taurus33 1.44 22 100%
Argopecten irradians18 2.00 16 97%
Sus scrofa23 3.65 18 99%
Xenopus laevis24 1.80 1 100%
Drosophila melanogaster21 1.70 4 100%
synthetic construct19 1.55 0 100%
Cryptosporidium parvum Iowa II16 1.84 15 98%

Seed sequence

149 residues, numbered every ten. Every identity figure in this document is measured against this sequence.

active or binding site modified residue or glycosylation disulphide cysteine transmembrane or signal the 15 most-substituted positions

1MADQLTEEQI AEFKEAFSLF DKDGDGTITT KELGTVMRSL GQNPTEAELQ DMINEVDADG
61NGTIDFPEFL TMMARKMKDT DSEEEIREAF RVFDKDGNGY ISAAELRHVM TNLGEKLTDE
121EVDEMIREAD IDGDGQVNYE EFVQMMTAK

Sites are UniProt's curated features where the seed is a UniProt accession; the substituted positions are measured from this family's own alignment rather than annotated, and only the fifteen most substituted are marked: every position carrying a minority substitution would be most of the protein, because the family holds orthologues. A residue can carry more than one and is drawn with the first that applies, in the order of the key above.

Primary citations

One record per paper, not per entry.

YearCitation
2026 icBTnC2, a new green calcium indicator based on troponin C and mBaoJin, with enhanced photostability. Protein Sci. doi:10.1002/pro.70499
2026 Lead Optimization of TgCDPK1 Inhibitors for the Treatment of Toxoplasmosis. J.Med.Chem. doi:10.1021/acs.jmedchem.6c00065
2026 The clinical missense variant E282K in PPP3CA/calcineurin shifts substrate dephosphorylation by altering active site recruitment. Nat Commun doi:10.1038/s41467-026-69535-5
2026 Structure-guided design of calcium-dependent protein kinase 1 (CDPK1) inhibitors for cryptosporidiosis. J.Infect.Dis. doi:10.1093/infdis/jiag242
2026 Structural identification of the RY12 domain of RyR1 as an ADP sensor and the target of the malignant hyperthermia therapeutic dantrolene Nat Commun doi:10.1038/s41467-026-76519-y
2026 Phosphorylation of a conserved aspartate in the catalytic site of eukaryotic elongation factor 2 kinase. Protein Sci. doi:10.1002/pro.70442
2026 Structural basis for the subtype-selectivity of K Ca 2.2 channel activators. Nat Commun doi:10.1038/s41467-025-67232-3
2026 Structural basis for the subtype-selective activation of K Ca 3.1 channels. Structure doi:10.1016/j.str.2026.04.010
2026 Structural mechanisms for inhibition and activation of human small-conductance Ca 2+ -activated potassium channel SK2. Nat Commun doi:10.1038/s41467-026-68475-4
2026 Cryo-EM structure of shutdown human nonmuscle myosin 2A. Sci Adv doi:10.1126/sciadv.aed1858
2026 Cryo-EM reveals how cardiomyopathy therapeutic drugs modulate the myosin motors of the heart. Sci Adv doi:10.1126/sciadv.aed6472
2026 Dynamics of the beta-cardiac myosin auto-inhibited state explain cardiomyopathy pathogenesis. Nat Commun doi:10.1038/s41467-026-73572-5
2026 Visualization of stepwise derepression of TFIIH in global genome nucleotide excision repair. Sci Adv doi:10.1126/sciadv.aeb3506
2026 Mechanism of lipid transfer by bridge-like protein VPS13A and the scramblase XK. Cell doi:10.1016/j.cell.2026.05.027
2026 Atomic models of the Toxoplasma cell invasion machinery. Nat.Struct.Mol.Biol. doi:10.1038/s41594-025-01728-w
2026 Comprehensive biophysical and structural profiling of alpha-actinin-2 variants reveals mechanistic diversity in hypertrophic cardiomyopathy. Nat Commun doi:10.1038/s41467-026-75392-z
2026 Structural and mechanistic insights into the UBR4-KCMF1-Calmodulin complex. Protein Cell doi:10.1093/procel/pwag036
2026 Cryo-EM structure of soluble VPS13C suggests its regulation by a conformational switch and by calmodulin. Mol.Cell doi:10.1016/j.molcel.2026.06.028
2026 Structural and kinetic mechanisms of state-dependent potassium channel inhibition Sci Adv
2026 Structural basis of nonmuscle myosin-2 autoinhibition mechanisms. Nat Commun doi:10.1038/s41467-026-74674-w
2026 Pre-incision structures reveal principles of DNA nucleotide excision repair. Nature doi:10.1038/s41586-026-10122-5
2026 The structure of the native cardiac crossbridge in the rigor state. Sci Adv doi:10.1126/sciadv.aeg1209
2026 Structural basis and functional analysis of NMDA receptor regulation by calmodulin. J.Biol.Chem. doi:10.1016/j.jbc.2026.111131
2026 Structural Insights into L-Type Voltage-Gated Ca 2+ Channel (Ca V 1.2) Activation by CaBP1. Biochemistry doi:10.1021/acs.biochem.6c00032
2025 Structural basis for the Ca 2+ /CaM-mediated regulation of CASK-CaMK. Int.J.Biol.Macromol. doi:10.1016/j.ijbiomac.2025.148495
2025 Bipartite Genetically Encoded Biosensors to Sense Calcium Ion Dynamics at Membrane-Membrane Contact Sites. Anal.Chem. doi:10.1021/acs.analchem.5c03831
2025 Potential Activation Mechanism of Calcium Indicator WHaloCaMP1a Revealed by the Crystal Structure and Molecular Dynamics Simulations. Biochemistry doi:10.1021/acs.biochem.5c00352
2025 Structural insights into the dual Ca 2+ -sensor-mediated activation of the PPEF phosphatase family. Nat Commun doi:10.1038/s41467-025-58261-z
2025 The critical role of the C-terminal lobe of calmodulin in activating eukaryotic elongation factor 2 kinase. J.Biol.Chem. doi:10.1016/j.jbc.2025.110650
2025 Phosphatidylinositol 4,5-bisphosphate activation mechanism of human KCNQ5. Proc.Natl.Acad.Sci.USA doi:10.1073/pnas.2416738122
2025 Targeting ryanodine receptors with allopurinol and xanthine derivatives for the treatment of cardiac and musculoskeletal weakness disorders. Proc.Natl.Acad.Sci.USA doi:10.1073/pnas.2422082122
2025 Visualizing insecticide control of insect TRP channel function and assembly. Nat Commun doi:10.1038/s41467-025-67287-2
2025 High-resolution structures of Myosin-IC reveal a unique actin-binding orientation, ADP release pathway, and power stroke trajectory. Proc.Natl.Acad.Sci.USA doi:10.1073/pnas.2415457122
2025 Mechanisms of KCNQ1 gating modulation by KCNE1/3 for cell-specific function. Cell Res. doi:10.1038/s41422-025-01152-1
2025 Structural mechanisms of assembly, gating, and calmodulin modulation of human olfactory CNG channel. Nat Commun doi:10.1038/s41467-025-64436-5
2025 Secondary structure transitions and dual PIP2 binding define cardiac KCNQ1-KCNE1 channel gating. Cell Res. doi:10.1038/s41422-025-01182-9
2025 Cryo-EM structures of the small-conductance Ca 2+ -activated K Ca 2.2 channel. Nat Commun doi:10.1038/s41467-025-59061-1
2025 Small molecule inhibits KCNQ channels with a non-blocking mechanism. Nat.Chem.Biol. doi:10.1038/s41589-024-01834-8
2025 Mechanism of SK2 channel gating and its modulation by the bee toxin apamin and small molecules. Elife doi:10.7554/eLife.107733
2025 Architecture of the UBR4 complex, a giant E4 ligase central to eukaryotic protein quality control. Science doi:10.1126/science.adv9309