X-group (possible homology)

6106 Photosystem II protein Y, psbY

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Ligands and drugs

231

Member domains

153

with ligand contacts (≤ 4 Å)

66.2% of members

118

with DrugDomain annotations

51.1% of members

118

with a DrugBank compound

51.1% 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)

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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
Lipids and lipid-like molecules	4	0.4	9.11×	not tested
Organoheterocyclic compounds	2	0.6	3.29×	not tested
Organic oxygen compounds	1	0.8	1.27×	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
DB18267	HEM	Ferroheme	103
DB03193	STE	Stearic acid	23
DB03317	HEC	Ferroheme C	15
DB03426	DGD	Digalactosyl Diacyl Glycerol (Dgdg)	12
DB04450	HTG	Heptyl 1-Thiohexopyranoside	1

Most frequently bound compounds

PDB ligand	Name	Domains in contact
HEM	PROTOPORPHYRIN IX CONTAINING FE	133
SQD	1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL	116
STE	STEARIC ACID	22
HEC	HEME C	16
DGD	DIGALACTOSYL DIACYL GLYCEROL (DGDG)	9
UNL	Unknown ligand	7
LMG	1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE	6
BCR	BETA-CAROTENE	4
CLA	CHLOROPHYLL A	4
HTG	heptyl 1-thio-beta-D-glucopyranoside	1