X-group (possible homology)

1189 VSG (variant surface glycoprotein) N-terminal domain and haptoglobin-hemoglobin receptor

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Ligands and drugs

362

Member domains

with ligand contacts (≤ 4 Å)

18.0% of members

with DrugDomain annotations

18.8% of members

with a DrugBank compound

14.9% 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	1	5.8	0.17×	q = 0.01
Organic oxygen compounds	8	2.4	3.40×	not tested
Homogeneous non-metal compounds	4	2.6	1.57×	not tested
Benzenoids	1	0.9	1.16×	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
DB00141	NAG	N-Acetylglucosamine	38
DB18267	HEM	Ferroheme	9
DB04786	SVR	Suramin	2

Most frequently bound compounds

PDB ligand	Name	Domains in contact
GLC	alpha-D-glucopyranose	30
NAG	2-acetamido-2-deoxy-beta-D-glucopyranose	25
HEM	PROTOPORPHYRIN IX CONTAINING FE	9
MAN	alpha-D-mannopyranose	6
BMA	beta-D-mannopyranose	5
BR	BROMIDE ION	3
CAmetal	CALCIUM ION	2
IOD	IODIDE ION	2
SVR	8,8'-[CARBONYLBIS[IMINO-3,1-PHENYLENECARBONYLIMINO(4-METHYL-3,1-PHENYLENE)CARBONYLIMINO]]BIS-1,3,5-NAPHTHALENETRISULFONIC ACID	2
I3C	5-amino-2,4,6-triiodobenzene-1,3-dicarboxylic acid	1