X-group (possible homology)

1074 Alpha helical domain of ribonucleotide reductases

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Ligands and drugs

392

Member domains

181

with ligand contacts (≤ 4 Å)

46.2% of members

with DrugDomain annotations

19.1% of members

with a DrugBank compound

16.6% 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
Nucleosides, nucleotides, and analogues	5	1.6	3.06×	not tested
Benzenoids	1	0.4	2.31×	not tested
Organic oxygen compounds	1	1.2	0.85×	not tested
Homogeneous metal compounds	1	2.9	0.34×	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
DB04555	CDP	Cytidine-5'-Diphosphate	18
DB04315	GDP	Guanosine-5'-Diphosphate	11
DB16833	ADP	Adenosine disphosphate	11
DB03222	DTP	dATP	7
DB03435	UDP	Uridine-5'-Diphosphate	5
DB00171	ATP	ATP	2
DB00242	—	Cladribine	1
DB00441	—	Gemcitabine	1
DB00631	—	Clofarabine	1
DB01005	—	Hydroxyurea	1
DB01073	—	—	1
DB02452	TTP	Thymidine 5'-triphosphate	1
DB05003	—	—	1
DB05420	—	—	1
DB06433	—	—	1

Most frequently bound compounds

PDB ligand	Name	Domains in contact
ATP	ADENOSINE-5'-TRIPHOSPHATE	94
GDP	GUANOSINE-5'-DIPHOSPHATE	69
DGI	2'-DEOXYGUANOSINE-5'-DIPHOSPHATE	20
CDP	CYTIDINE-5'-DIPHOSPHATE	18
ADP	ADENOSINE-5'-DIPHOSPHATE	11
DTP	2'-DEOXYADENOSINE 5'-TRIPHOSPHATE	9
UDP	URIDINE-5'-DIPHOSPHATE	5
DAT	2'-DEOXYADENOSINE-5'-DIPHOSPHATE	4
TTP	THYMIDINE-5'-TRIPHOSPHATE	2
2A5	2'-deoxy-2'-(2-hydroxyethyl)adenosine 5'-(trihydrogen diphosphate)	1
7LL	2-hydroxy-N'-[(Z)-(2-hydroxynaphthalen-1-yl)methylidene]benzohydrazide	1
A1A3L	4-amino-1-{(3xi)-3-C-amino-2-deoxy-5-O-[(S)-hydroxy(phosphonooxy)phosphoryl]-beta-D-threo-pentofuranosyl}pyrimidin-2(1H)-one	1
GCQ	GEMCITABINE DIPHOSPHATE	1
MGmetal	MAGNESIUM ION	1