X-group (possible homology)

5063 Photosystem I reaction center subunit X, PsaK

Ligands and drugs

363
Member domains
243
with ligand contacts (≤ 4 Å)
66.9% of members
184
with DrugDomain annotations
50.7% of members
181
with a DrugBank compound
49.9% 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.

37
Proteins with classified ligands
3
Superclasses bound (of 23)
2.5
Superclasses per 20 proteins
narrower than 97% 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.

SuperclassProteinsExpected
0.25×observed / expected4×
RatioSignificance
Organoheterocyclic compounds375.66.59×q < 0.0001
Homogeneous metal compounds017.90q < 0.0001
Homogeneous non-metal compounds07.90q = 9.3e-4
Nucleosides, nucleotides, and analogues010.10q < 0.0001
Organic acids and derivatives05.60q = 9.2e-3
Organic oxygen compounds07.30q = 1.5e-3
Lipids and lipid-like molecules334.18.12×not tested
Organic nitrogen compounds11.20.86×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

DrugBankPDB ligandNameDomains
DB02133CLAChlorophyll A180
DB06755BCRBeta carotene144
DB03279LMUDodecyl-Alpha-D-Maltoside21
DB00137LUT(3R,3'R,6S)-4,5-DIDEHYDRO-5,6-DIHYDRO-BETA,BETA-CAROTENE-3,3'-DIOL10
DB02043LHG1,2-Dipalmitoyl-Phosphatidyl-Glycerole7
DB04506CHLChlorophyll B7
DB01707LAPL-Alfa-Lysophosphatidylcholine, Lauroyl2
DB03017DAOLauric acid2
DB03426DGDDigalactosyl Diacyl Glycerol (Dgdg)2
DB04038ERGErgosterol2
DB03690PCW(Z,Z)-4-Hydroxy-N,N,N-Trimethyl-10-Oxo-7-[(1-Oxo-9-Octadecenyl)Oxy]-3,5,9-Trioxa-4-Phosphaheptacos-18-En-1-Aminium-4-Oxide1
DB15914RRXCryptoxanthin1

Most frequently bound compounds

PDB ligandNameDomains in contact
CLACHLOROPHYLL A238
BCRBETA-CAROTENE215
LMG1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE38
LHG1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE22
LMUDODECYL-ALPHA-D-MALTOSIDE22
CHLCHLOROPHYLL B19
SQD1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL12
LUT(3R,3'R,6S)-4,5-DIDEHYDRO-5,6-DIHYDRO-BETA,BETA-CAROTENE-3,3'-DIOL11
8CT(6'R,11cis,11'cis,13cis,15cis)-4',5'-didehydro-5',6'-dihydro-beta,beta-carotene9
WVN1,3,3-trimethyl-2-[(1E,3E,5E,7E,9E,11E,13E,15E,17E)-3,7,12,16-tetramethyl-18-[(1R)-2,6,6-trimethylcyclohex-2-en-1-yl]octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohexene6
DGDDIGALACTOSYL DIACYL GLYCEROL (DGDG)5
AJPDigitonin4
DD6(3S,3'R,5R,6S,7cis)-7',8'-didehydro-5,6-dihydro-5,6-epoxy-beta,beta-carotene-3,3'-diol4
C7Z(1~{S})-3,5,5-trimethyl-4-[(1~{E},3~{E},5~{E},7~{E},9~{E},11~{E},13~{E},15~{E},17~{E})-3,7,12,16-tetramethyl-18-[(4~{S})-2,6,6-trimethyl-4-oxidanyl-cyclohexen-1-yl]octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohex-3-en-1-ol3
CL7CHLOROPHYLL D3
IHT(1~{R})-3,5,5-trimethyl-4-[(3~{E},5~{E},7~{E},9~{E},11~{E},13~{E},15~{E},17~{E})-3,7,12,16-tetramethyl-18-(2,6,6-trimethylcyclohexen-1-yl)octadeca-3,5,7,9,11,13,15,17-octaen-1-ynyl]cyclohex-3-en-1-ol3
SPHSPHINGOSINE3
DAOLAURIC ACID2
ERGERGOSTEROL2
KC2Chlorophyll c22