X-group (possible homology)

73 SMAD/FHA domain

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Ligands and drugs

1,331

Member domains

with ligand contacts (≤ 4 Å)

6.3% of members

with DrugDomain annotations

6.0% of members

with a DrugBank compound

4.2% of members

Aggregated over all current member domains of this group. Drug annotations come from DrugDomain; buffers and crystallization additives are excluded from the tables below.

Chemical profile

ClassyFire chemical superclasses of the ligands bound by this X-group's proteins, from DrugDomain annotations.

Proteins with classified ligands

Superclasses bound (of 23)

—

Superclasses per 20 proteins

fewer than 20 proteins: too few to compare at equal depth

The raw number of superclasses rises with the number of proteins sampled; the per-20 value compares X-groups at equal depth.

Superclass	Proteins	Expected	Ratio	Significance
Homogeneous metal compounds	6	7.3	0.83×	q = 0.69
Organosulfur compounds	1	0.3	3.29×	not tested
Mixed metal/non-metal compounds	1	0.3	3.22×	not tested
Homogeneous non-metal compounds	6	3.2	1.89×	not tested
Organic acids and derivatives	1	2.3	0.44×	not tested
Organic oxygen compounds	1	3.0	0.34×	not tested
Nucleosides, nucleotides, and analogues	1	4.1	0.24×	not tested

enriched (q < 0.05)depleted (q < 0.05)not significantnot tested (expected < 5)

Unit: a protein (UniProt accession) with a ligand-binding domain in this X-group, counted once per superclass. Expected counts use each superclass's frequency across all ligand-binding X-groups; significance is Fisher's exact test with Benjamini–Hochberg correction. Buffers and crystallization additives are excluded. ECOD v295.2; the method follows the ECOD 2027 update, whose published figures used a slightly different artifact filter.

DrugBank compounds

DrugBank	PDB ligand	Name	Domains
DB03909	ACP	Adenosine-5'-[Beta, Gamma-Methylene]Triphosphate	2
DB00160	ALA	Alanine	1
DB01694	TAR	D-tartaric acid	1
DB04395	—	Phosphoaminophosphonic Acid-Adenylate Ester	1
DB04522	—	Dexfosfoserine	1
DB06486	—	—	1
DB12010	—	Fostamatinib	1

Most frequently bound compounds

PDB ligand	Name	Domains in contact
CL	CHLORIDE ION	11
UNX	UNKNOWN ATOM OR ION	5
HX2	(2R,5R)-hexane-2,5-diol	4
CAmetal	CALCIUM ION	3
ADP	ADENOSINE-5'-DIPHOSPHATE	2
MGmetal	MAGNESIUM ION	2
SCN	THIOCYANATE ION	2
NAmetal	SODIUM ION	1
NImetal	NICKEL (II) ION	1
TAR	D(-)-TARTARIC ACID	1
WO4	TUNGSTATE(VI)ION	1
ZNmetal	ZINC ION	1