X-group (possible homology)

230 T-fold

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Ligands and drugs

9,961

Member domains

1,516

with ligand contacts (≤ 4 Å)

15.2% of members

1,125

with DrugDomain annotations

11.3% of members

709

with a DrugBank compound

7.1% 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)

7.3

Superclasses per 20 proteins

narrower than 57% of the 256 X-groups with enough proteins to compare (median 7.6)

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
Organoheterocyclic compounds	26	10.2	2.56×	q < 0.0001
Homogeneous metal compounds	44	32.4	1.36×	q = 9.8e-3
Nucleosides, nucleotides, and analogues	18	18.3	0.99×	q = 1.00
Homogeneous non-metal compounds	11	14.2	0.77×	q = 0.45
Organic acids and derivatives	7	10.2	0.69×	q = 0.47
Organic oxygen compounds	6	13.2	0.46×	q = 0.05
Lipids and lipid-like molecules	0	7.4	0	q = 1.7e-3
Mixed metal/non-metal compounds	3	1.4	2.16×	not tested
Organosulfur compounds	1	1.4	0.74×	not tested
Benzenoids	2	4.8	0.41×	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
DB01875	AZA	8-azaxanthine	151
DB04137	GTP	Guanosine-5'-Triphosphate	75
DB09140	OXY	Oxygen	65
DB00120	PHE	Phenylalanine	55
DB02377	GUN	Guanine	47
DB04400	HBI	7,8-dihydrobiopterin	40
DB08844	URC	Uric acid	29
DB03304	PRF	7-Deaza-7-Aminomethyl-Guanine	28
DB02119	PH2	6-Hydroxymethyl-7,8-Dihydropterin	23
DB02806	MXE	2-Methoxyethanol	21
DB03147	FAD	Flavin adenine dinucleotide	20
DB03461	NAP	Nicotinamide adenine dinucleotide phosphate	16
DB03886	BIO	Biopterin	14
DB04380	1AL	Allantoate	14
DB03293	MUA	9-Methyl Uric Acid	13
DB16833	ADP	Adenosine disphosphate	12
DB06690	N2O	Nitrous oxide	11
DB03896	3PO	Triphosphoric acid	10
DB02489	9MG	9-Methylguanine	9
DB03099	UNC	5-Amino 6-Nitro Uracil	9

Most frequently bound compounds

PDB ligand	Name	Domains in contact
MGmetal	MAGNESIUM ION	392
ZNmetal	ZINC ION	227
AZA	8-AZAXANTHINE	195
NAmetal	SODIUM ION	93
OXY	OXYGEN MOLECULE	87
CL	CHLORIDE ION	82
GTP	GUANOSINE-5'-TRIPHOSPHATE	76
OHX	osmium (III) hexammine	70
QBQ	7-deaza-GTP	60
PHE	PHENYLALANINE	55
GUN	GUANINE	46
HBI	7,8-DIHYDROBIOPTERIN	40
CAmetal	CALCIUM ION	31
PRF	7-DEAZA-7-AMINOMETHYL-GUANINE	28
URC	URIC ACID	26
XE	XENON	24
PH2	2-AMINO-6-HYDROXYMETHYL-7,8-DIHYDRO-3H-PTERIDIN-4-ONE	23
AR	ARGON	22
MXE	2-METHOXYETHANOL	22
FAD	FLAVIN-ADENINE DINUCLEOTIDE	20