X-group (possible homology)

5030 Photosystem II reaction center protein L, PsbL

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Ligands and drugs

381

Member domains

335

with ligand contacts (≤ 4 Å)

87.9% of members

242

with DrugDomain annotations

63.5% of members

218

with a DrugBank compound

57.2% 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)

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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
Homogeneous metal compounds	0	7.7	0	q = 1.2e-4
Lipids and lipid-like molecules	16	1.8	9.11×	not tested
Hydrocarbons	1	0.1	9.07×	not tested
Organoheterocyclic compounds	7	2.4	2.88×	not tested
Organic oxygen compounds	1	3.1	0.32×	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
DB02043	LHG	1,2-Dipalmitoyl-Phosphatidyl-Glycerole	208
DB02133	CLA	Chlorophyll A	63
DB03193	STE	Stearic acid	48
DB03426	DGD	Digalactosyl Diacyl Glycerol (Dgdg)	14
DB04735	MGE	Monogalactosyldiacylglycerol	10
DB06755	BCR	Beta carotene	4
DB04450	HTG	Heptyl 1-Thiohexopyranoside	1

Most frequently bound compounds

PDB ligand	Name	Domains in contact
CLA	CHLOROPHYLL A	326
PL9	2,3-DIMETHYL-5-(3,7,11,15,19,23,27,31,35-NONAMETHYL-2,6,10,14,18,22,26,30,34-HEXATRIACONTANONAENYL-2,5-CYCLOHEXADIENE-1,4-DIONE-2,3-DIMETHYL-5-SOLANESYL-1,4-BENZOQUINONE	321
LMG	1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE	309
LHG	1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE	298
SQD	1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL	290
STE	STEARIC ACID	49
UNL	Unknown ligand	41
DGD	DIGALACTOSYL DIACYL GLYCEROL (DGDG)	15
BCR	BETA-CAROTENE	10
MGE	(1S)-2-(ALPHA-L-ALLOPYRANOSYLOXY)-1-[(TRIDECANOYLOXY)METHYL]ETHYL PALMITATE	10
CL7	CHLOROPHYLL D	8
PQ9	5-[(2E,6E,10E,14E,18E,22E)-3,7,11,15,19,23,27-HEPTAMETHYLOCTACOSA-2,6,10,14,18,22,26-HEPTAENYL]-2,3-DIMETHYLBENZO-1,4-QUINONE	8
3PH	1,2-DIACYL-GLYCEROL-3-SN-PHOSPHATE	4
F6C	Chlorophyll F	2
PLM	PALMITIC ACID	2
HTG	heptyl 1-thio-beta-D-glucopyranoside	1