CODSWALLOP

Polyubiquitin-C

Homo sapiens · seed P0CG48 · 685 aa · family defined as ≥30% identity to that seed · compiled 07 October 2026

CATH and SCOP identifiers come from the RCSB's own structure annotations, which the Domains panel already reads, so these are looked up rather than guessed at.

1,619Entries 1,999Entities 362Constructs 64Organisms 738Ligand-bound
0.85 ÅBest res.
2.90 ÅMedian res.

Every figure here is counted over the whole family rather than quoted from one entry.

The reference structure

4P4H, the structure every other member of this family is superposed onto. Rendered by the RCSB and embedded here: the live app shows an interactive viewport, which a document that fetches nothing cannot.

Rendered structure of 4P4H
4P4H at the RCSB · open it in the 3D viewer

Which residues anyone has ever seen

How many of this family's constructs contain each residue of the seed. A trough is a stretch nobody has put in a construct, which is a construct-design answer rather than a disorder one.

13426851624 constructs

Constructs, most-used first

362 distinct constructs across 1,619 entries. 1,157 polymer entities differ from the UniProt canonical sequence in some way, 40 carry a recognised expression tag and 0 carry a fusion partner.

"Differs from canonical" is not the same as "engineered". The canonical sequence is the full gene product, so a secreted protein whose structures all start after its signal peptide counts every one of them as different: lysozyme's most-used construct, residues 19–147 on 1,239 entities, is simply the mature protein. Read the construct column below for what was actually done, rather than this count.

EntitiesLengthBest (Å)Best entryWhat was made
383 76 0.85 6Q00 residues 609-684
199 156 1.67 8GLP matches the canonical sequence
145 128 1.67 8GLP matches the canonical sequence
99 128 1.75 9PN5 matches the canonical sequence
76 152 1.75 9PN5 matches the canonical sequence
71 75 1.44 8ST7 residues 609-683
50 133 2.50 8SCB matches the canonical sequence
48 76 1.85 8EFX residues 609-684; G684C
35 76 1.85 8HTD residues 305-380
32 76 1.45 4IUM residues 609-684
32 102 2.69 8RJB residues 30-128; 3-residue insertion after 35; I30M, Q31G, K33P +1 more
29 79 2.50 9B5C residues 1-75
26 188 2.70 8VVQ M1A, Q2A, I3L +27 more
24 76 1.60 1NDD residues 1-76
20 76 1.18 3A9J residues 609-684; K671R
20 77 1.18 3A9J residues 609-685; V685D
18 793 3.00 8I0R matches the canonical sequence
17 150 3.02 6FYY matches the canonical sequence
17 193 2.15 9G6J matches the canonical sequence
15 76 1.25 7S6O residues 609-684; K656R
13 80 2.93 8G6G residues 1-76; G76C
13 81 1.40 9FJ3 residues 604-684; R604G, L605S, R606G +1 more
13 152 1.70 3B08 residues 533-684
11 81 2.96 9EFQ matches the canonical sequence
11 81 3.60 8TXW residues 1-76

Showing the 25 most-used of 362.

Positions people deliberately mutate

Columns where the wild-type residue still dominates but a real minority carries something else, which is a different question from "what varies across species".

P627S 25% A636S 24% E632D 24% Q639A 12% I638V 11% K671A 11% S628T 11% V634I 11% S665A 10% D640E 10% K637R 10% I631V 10% E672L 10% N633Q 10% Q670E 10% T620E 10% R662K 10% K641L 9% N668G 9% K619E 9% G661E 8% K614R 8% T617A 8% I621H 8% Q610L 8% E626T 8% T622E 7% E624D 7% L623I 7% G684C 7%

What it assembles into

Oligomeric stateChainsEntriesShare
dimeric2 364 22.5%
trimeric3 189 11.7%
monomeric1 156 9.6%
tetrameric4 101 6.2%
80-meric80 42 2.6%
82-meric82 33 2.0%
dodecameric12 32 2.0%
83-meric83 31 1.9%

643 entries have the depositor's assembly corroborated by PISA, 940 carry the depositor's word alone and 34 were assigned by PISA where the depositor gave none. The middle figure is not a disagreement: PISA may have returned nothing or never run. 78 entries carry more than one assembly with different chain counts, so they have no single answer to quote: 1NBF, 1NDD, 1P3Q, 1WRD, 1YIW, 1YJ1, 2AYO, 2BWE, 2GBK, 2GBR, 2ZCB, 2ZCC, 3DQV, 3EEC, 3H7S, 3K9P, 3LDZ, 3NS8, 3O65, 3OJ3.

Domain architecture

Every source's own domains on the seed axis, one row each. They are not merged: Pfam, CATH, SCOP and InterPro disagree about boundaries, and a merged track would state a consensus none of them gave.

CATHPhosphatidylinositol 3-kinSCOP2BUbiquitin-likeUbiquitin-likeUbiquitin-likeUbiquitin-likeUbiquitin-likeUbiquitin-like1342685
DomainSourceSpan (seed)Chains
Phosphatidylinositol 3-kinase Catalytic Subunit; Chain A, domain 1CATH 3.10.20.90 77–152 407
Ubiquitin-likeSCOP2B 8043829 77–151 285
Ubiquitin-likeSCOP2B 8101457 77–151 206
Ubiquitin-likeSCOP2B 8066187 77–152 37
Ubiquitin-likeSCOP2B 8098440 77–150 24
Ubiquitin-likeSCOP2B 8034470 77–150 22
Ubiquitin-likeSCOP2B 8093606 79–153 21

What binds it

ATP ATP113 entries ADP ADP69 entries GTP GTP54 entries MET MET38 entries AMP AMP33 entries IHP IHP32 entries GDP GDP31 entries A1AIV A1AIV29 entries AYE AYE28 entries GCP GCP27 entries SPM SPM25 entries 3HE 3HE21 entries
ComponentClassNameEntriesBest (Å)
ZNion Zinc Ion 809 1.18
MGion Magnesium Ion 469 0.85
ATPcofactor Adenosine-5'-Triphosphate 113 1.77
Kion Potassium Ion 110 0.85
SPDcryoprotectant Spermidine 103 1.67
GOLcryoprotectant Glycerol 85 1.15
SO4ion Sulfate Ion 78 1.08
ADPcofactor Adenosine-5'-Diphosphate 69 2.40
EDOcryoprotectant 1,2-Ethanediol 63 0.85
CLion Chloride Ion 56 1.30
GTPcofactor Guanosine-5'-Triphosphate 54 2.57
NAion Sodium Ion 52 1.40
METligand Methionine 38 1.67
AMPcofactor Adenosine Monophosphate 33 2.22
IHPligand Inositol Hexakisphosphate 32 2.25
GDPcofactor Guanosine-5'-Diphosphate 31 2.04
A1AIVligand 4-Aminobutanenitrile 29 2.50
AYEligand Prop-2-En-1-Amine 28 1.44
GCPligand Phosphomethylphosphonic Acid Guanylate Ester 27 3.00
SPMligand Spermine 25 1.67

How it crystallises

Parsed from the free text 645 depositors typed into _exptl_crystal_grow.pdbx_details, out of 650 entries that recorded anything at all. Median pH 7.0 (range 2.8 to 10.0).

Precipitants

PEG × Ammonium sulfate × Sodium chloride × Sodium citrate × Magnesium chloride × Lithium sulfate × MPD × Calcium chloride × Isopropanol × Sodium malonate × Tacsimate × PEG (unspecified) × Sodium formate × Dioxane ×

Buffers

Tris × Citrate × HEPES × MES × Bis-Tris × Sodium acetate × Bis-Tris propane × Sodium cacodylate × Phosphate × Imidazole × CHES × Glycine ×

Which entries to trust

1,600 entries carry a wwPDB validation report: 973 clean, 354 worth a check and 273 with something to explain. Median clashscore 6.3, median RSRZ outliers 3.32%, median R-free minus R-work 0.041. 1,576 have released structure factors.

Across species

OrganismEntriesBest (Å)Ligand-boundSeed covered
Homo sapiens1,038 0.85 365 100%
Oryctolagus cuniculus115 2.20 115 31%
Saccharomyces cerevisiae109 1.15 107 34%
Mus musculus42 1.18 11 34%
Bos taurus49 0.85 6 22%
Saccharomyces cerevisiae S288C42 1.85 21 24%
Schizosaccharomyces pombe 972h-33 2.20 43 11%
synthetic construct14 1.39 0 23%
Kluyveromyces lactis NRRL Y-114012 3.02 11 11%
Triticum aestivum10 2.06 5 23%
Thermochaetoides thermophila DSM 14956 2.20 7 22%
Plasmodium falciparum 3D710 2.30 1 11%

Seed sequence

685 residues, numbered every ten. Every identity figure in this document is measured against this sequence.

active or binding site modified residue or glycosylation disulphide cysteine transmembrane or signal the 15 most-substituted positions

1MQIFVKTLTG KTITLEVEPS DTIENVKAKI QDKEGIPPDQ QRLIFAGKQL EDGRTLSDYN
61IQKESTLHLV LRLRGGMQIF VKTLTGKTIT LEVEPSDTIE NVKAKIQDKE GIPPDQQRLI
121FAGKQLEDGR TLSDYNIQKE STLHLVLRLR GGMQIFVKTL TGKTITLEVE PSDTIENVKA
181KIQDKEGIPP DQQRLIFAGK QLEDGRTLSD YNIQKESTLH LVLRLRGGMQ IFVKTLTGKT
241ITLEVEPSDT IENVKAKIQD KEGIPPDQQR LIFAGKQLED GRTLSDYNIQ KESTLHLVLR
301LRGGMQIFVK TLTGKTITLE VEPSDTIENV KAKIQDKEGI PPDQQRLIFA GKQLEDGRTL
361SDYNIQKEST LHLVLRLRGG MQIFVKTLTG KTITLEVEPS DTIENVKAKI QDKEGIPPDQ
421QRLIFAGKQL EDGRTLSDYN IQKESTLHLV LRLRGGMQIF VKTLTGKTIT LEVEPSDTIE
481NVKAKIQDKE GIPPDQQRLI FAGKQLEDGR TLSDYNIQKE STLHLVLRLR GGMQIFVKTL
541TGKTITLEVE PSDTIENVKA KIQDKEGIPP DQQRLIFAGK QLEDGRTLSD YNIQKESTLH
601LVLRLRGGMQ IFVKTLTGKT ITLEVEPSDT IENVKAKIQD KEGIPPDQQR LIFAGKQLED
661GRTLSDYNIQ KESTLHLVLR LRGGV

Sites are UniProt's curated features where the seed is a UniProt accession; the substituted positions are measured from this family's own alignment rather than annotated, and only the fifteen most substituted are marked: every position carrying a minority substitution would be most of the protein, because the family holds orthologues. A residue can carry more than one and is drawn with the first that applies, in the order of the key above.

Primary citations

One record per paper, not per entry.

YearCitation
2026 Mesostructured Water Enhances Stability of ProteinMPNN-Designed Ubiquitin-Fold Proteins. J.Am.Chem.Soc. doi:10.1021/jacs.5c19875
2026 2'-O-Methylation maintains ribosome structural and translation integrity. Mol.Cell doi:10.1016/j.molcel.2026.03.008
2026 Recruitment of bifunctional regulator thermospermine to methylated ribosomes directs xylem fate. Science doi:10.1126/science.adx2867
2026 Context-dependent translation inhibition as a cancer therapeutic modality. Nat Commun doi:10.1038/s41467-026-69891-2
2026 An Epstein-Barr virus-encoded snoRNA directs 2'-O-methylation of human rRNAs to control translation and the viral lytic switch. Cell Rep doi:10.1016/j.celrep.2026.117814
2026 Structural basis of co-translational N-myristoylation in humans. Nat Commun doi:10.1038/s41467-025-67962-4
2026 A small nucleolar RNA dictates the structure and function of translating ribosomes in Leishmania. Nat Commun doi:10.1038/s41467-026-75486-8
2026 Structural insights into ubiquitin recognition by USP15 revealed through a covalent activity-based probe. Commun Biol doi:10.1038/s42003-026-10386-7
2026 ZAK activation at the collided ribosome. Nature doi:10.1038/s41586-025-09772-8
2026 N 1 -Methylpseudouridine directly modulates translation dynamics. Nature doi:10.1038/s41586-025-09945-5
2026 human 80S ribosome non-rotated state Nucleic Acids Res.
2026 Structural and molecular basis of specialized translation mediated by the ribosome mRNA-binding channel. Nat Commun doi:10.1038/s41467-026-72263-5
2026 UBA6 specificity for ubiquitin E2 conjugating enzymes reveals a priority mechanism of BIRC6. Nat.Struct.Mol.Biol. doi:10.1038/s41594-025-01717-z
2026 Structure and mechanism of an actin-dependent bacterial phosphoryl AMPylase. Nat.Chem.Biol. doi:10.1038/s41589-025-01945-w
2026 NAA40 and NAC cooperate in co-translational histone acetylation in humans. Nat Commun doi:10.1038/s41467-026-70279-5
2026 human 80S ribosome rotated state Nucleic Acids Res.
2026 NAC promotes co-translational protein folding at the ribosomal tunnel exit. Mol.Cell doi:10.1016/j.molcel.2026.02.022
2026 ISGylation mechanism uncovers conformational specificity for HECT-family E3 ligase HERC5. Cell Rep doi:10.1016/j.celrep.2026.117565
2026 Cryo-EM structures of UBA6 reveal mechanisms of E1-E2 specificity and dual FAT10/ubiquitin thioester transfer. Nat Commun doi:10.1038/s41467-026-69882-3
2026 Structural determinants for FAT10 activation and transfer from UBA6 to E2 enzymes. Nat Commun doi:10.1038/s41467-026-76603-3
2026 A RiboCancer cell line panel reveals that CLL-associated Rps15 mutations translationally rewire transcription through codon-specific tRNA accommodation defects. Hemasphere doi:10.1002/hem3.70377
2026 Translation initiation by the Kozak mRNA sequence is based on a conformational readout on the ribosome. Nat Commun doi:10.1038/s41467-026-73969-2
2026 Mechanism of ribosome stalling by the AMD1 C-terminal tail arrest peptide. Sci Adv doi:10.1126/sciadv.aec5067
2026 Cryo-EM structure of the naked mole-rat ribosome reveals a stabilized split 28S rRNA. Nat Commun doi:10.1038/s41467-026-75143-0
2026 Cryo-EM structure of the Arabidopsis thaliana ribosome in translating and non-translating states. Structure doi:10.1016/j.str.2026.06.001
2026 Mechanism of K63-linked polyubiquitin recognition and cleavage by the BRCA1-A complex. Nat Commun doi:10.1038/s41467-026-75795-y
2026 Cysteine availability tunes ubiquitin signaling via inverse stability of LRRC58 E3 ligase and its substrate CDO1. Nat Commun doi:10.1038/s41467-026-72524-3
2026 CSN5i-3 is an orthosteric molecular glue inhibitor of COP9 signalosome. Nature doi:10.1038/s41586-026-10129-y
2026 E2 variants for probing E3 ubiquitin ligase activities. Proc.Natl.Acad.Sci.USA doi:10.1073/pnas.2524899122
2026 The deubiquitinating enzyme Otu1 releases substrates from the conserved initiation complex of the Cdc48/p97 ATPase for proteasomal degradation. Sci Rep doi:10.1038/s41598-026-42811-6
2026 Human DHX29 detects nonoptimal codon usage to regulate mRNA stability. Science doi:10.1126/science.adw0288
2026 A ubiquitin chain-feeding mechanism for BRCA1-A. Nat Commun doi:10.1038/s41467-026-75797-w
2026 Nucleoplasmic checkpoint of the 40S ribosomal decoding center maturation. Cell Rep doi:10.1016/j.celrep.2026.117545
2026 The maternal PADI6-UHRF1-UBE2D complex regulates ubiquitination during oocyte maturation and embryogenesis. Nat.Struct.Mol.Biol. doi:10.1038/s41594-026-01758-y
2026 Structure and mechanism of the HECT ligase HECTD3. Nat Commun doi:10.1038/s41467-026-69520-y
2026 Insight into the scaffolding function of USP18 from a high resolution cryo-EM structure of STAT2-USP18-ISG15 ternary complex Biorxiv doi:10.64898/2026.02.12.705587
2026 The mechanism of ribosomal recruitment during translation initiation on the Type 2 encephalomyocarditis virus IRES. Embo J. doi:10.1038/s44318-026-00735-x
2026 Evolution of a core ribosomal innovation in octopus. Curr.Biol. doi:10.1016/j.cub.2026.07.008
2026 Molecular mechanism of HUWE1-HAPSTR1-USP7-mediated ubiquitin chain amplification on nuclear proteins. Mol.Cell doi:10.1016/j.molcel.2026.08.016
2026 Structural basis of regulated N-glycosylation at the secretory translocon. Nature doi:10.1038/s41586-025-09756-8