X-group (possible homology)

1042 S2 subunit of coronavirus spike glycoprotein

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Ligands and drugs

3,978

Member domains

2,855

with ligand contacts (≤ 4 Å)

71.8% of members

2,168

with DrugDomain annotations

54.5% of members

2,168

with a DrugBank compound

54.5% 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)

3.2

Superclasses per 20 proteins

narrower than 94% 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
Organic oxygen compounds	27	5.3	5.09×	q < 0.0001
Homogeneous metal compounds	0	13.1	0	q < 0.0001
Homogeneous non-metal compounds	0	5.7	0	q = 7.0e-3
Nucleosides, nucleotides, and analogues	0	7.4	0	q = 8.2e-4
Benzenoids	1	2.0	0.51×	not tested
Lipids and lipid-like molecules	1	3.0	0.34×	not tested
Organic acids and derivatives	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
DB00141	NAG	N-Acetylglucosamine	2,168
DB00149	LEU	Leucine	6
DB04257	PAM	Palmitoleic Acid	3
DB04473	FUC	alpha-L-fucose	2

Most frequently bound compounds

PDB ligand	Name	Domains in contact
NAG	2-acetamido-2-deoxy-beta-D-glucopyranose	2,849
PAM	PALMITOLEIC ACID	7
ZNmetal	ZINC ION	7
GE9	2,3,5-tris(iodanyl)benzamide	3
MAN	alpha-D-mannopyranose	3
FUC	alpha-L-fucopyranose	2
CAmetal	CALCIUM ION	1