| PF00021 | UPAR_LY6 | u-PAR/Ly-6 domain | P13987 |
| PF00179 | UQ_con | Ubiquitin-conjugating enzyme | P68036 |
| PF00201 | UDPGT | UDP-glucoronosyl and UDP-glucosyl transferase | Q9SBL1 |
| PF00240 | ubiquitin | Ubiquitin family | Q15459 |
| PF00443 | UCH | Ubiquitin carboxyl-terminal hydrolase | Q70CQ3 |
| PF00449 | Urease_alpha | Urease alpha-subunit, N-terminal domain | P41020 |
| PF00547 | Urease_gamma | Urease, gamma subunit | P41022 |
| PF00577 | Usher | Outer membrane usher protein | P07110 |
| PF00580 | UvrD-helicase | UvrD/REP helicase N-terminal domain | A0A024LB08 |
| PF00582 | Usp | Universal stress protein family | A0A0H2Z9V8 |
| PF00627 | UBA | UBA/TS-N domain | P27448 |
| PF00699 | Urease_beta | Urease beta subunit | P41021 |
| PF00789 | UBX | UBX domain | O35987 |
| PF00919 | UPF0004 | Uncharacterized protein family UPF0004 | A0A174GYG1 |
| PF00984 | UDPG_MGDP_dh | UDP-glucose/GDP-mannose dehydrogenase family, central domain | Q0P8H3 |
| PF01014 | Uricase | Uricase | Q00511 |
| PF01040 | UbiA | UbiA prenyltransferase family | G3IEF0 |
| PF01099 | Uteroglobin | Uteroglobin family | P11684 |
| PF01170 | UPF0020 | RMKL-like, methyltransferase domain | O29011 |
| PF01175 | Urocanase | Urocanase Rossmann-like domain | A0A0Q9KFZ4 |
| PF01205 | UPF0029 | Uncharacterized protein family UPF0029 | P25637 |
| PF01208 | URO-D | Uroporphyrinogen decarboxylase (URO-D) | B2FQJ0 |
| PF01209 | Ubie_methyltran | ubiE/COQ5 methyltransferase family | Q4X158 |
| PF01704 | UDPGP | UTP--glucose-1-phosphate uridylyltransferase | Q4WAM5 |
| PF01730 | UreF | UreF | A6TE44 |
| PF01774 | UreD | UreD urease accessory protein | Q09067 |
| PF01893 | UPF0058 | Uncharacterised protein family UPF0058 | Q9HQM9 |
| PF01894 | UPF0047 | Uncharacterised protein family UPF0047 | Q9YBS9 |
| PF01977 | UbiD | 3-octaprenyl-4-hydroxybenzoate carboxy-lyase Rift-related domain | A0A0N9Y7U2 |
| PF02021 | UPF0102 | Uncharacterised protein family UPF0102 | Q6NCZ4 |
| PF02083 | Urotensin_II | Urotensin II | O95399 |
| PF02151 | UVR | UvrB/uvrC motif | P37954 |
| PF02271 | UCR_14kD | Ubiquinol-cytochrome C reductase complex 14kD subunit | A0A1S3U9J1 |
| PF02320 | UCR_hinge | Ubiquinol-cytochrome C reductase hinge protein | A0A1S3VHC0 |
| PF02393 | US22 | US22 like | |
| PF02614 | UxaC | Glucuronate isomerase | D5SMT1 |
| PF02694 | UPF0060 | Uncharacterised BCR, YnfA/UPF0060 family | |
| PF02809 | UIM | Ubiquitin interaction motif | P55036 |
| PF02814 | UreE_N | UreE urease accessory protein, N-terminal domain | P50049 |
| PF02921 | UCR_TM | Ubiquinol cytochrome reductase transmembrane region | A0A1S3TB49 |
| PF02939 | UcrQ | UcrQ family | Q6C387 |
| PF03152 | UFD1_N1 | Ubiquitin fusion degradation protein UFD1, N-terminal subdomain 1 | P53044 |
| PF03167 | UDG | Uracil DNA glycosylase superfamily | P13051 |
| PF03253 | UT | Urea transporter | Q13336 |
| PF03350 | UPF0114 | Uncharacterized protein family, UPF0114 | |
| PF03456 | uDENN | uDENN domain | Q8TEH3 |
| PF03649 | UPF0014 | Uncharacterised protein family (UPF0014) | |
| PF03653 | UPF0093 | Uncharacterised protein family (UPF0093) | |
| PF03657 | UPF0113 | UPF0113 PUA domain | Q1MTQ9 |
| PF03658 | Ub-RnfH | RnfH family Ubiquitin | Q4QNE7 |
| PF03665 | UPF0172 | Uncharacterised protein family (UPF0172) | O43402 |
| PF03670 | UPF0184 | Uncharacterised protein family (UPF0184) | |
| PF03671 | Ufm1 | Ubiquitin fold modifier 1 protein | P61960 |
| PF03672 | UPF0154 | Uncharacterised protein family (UPF0154) | |
| PF03673 | UPF0128 | Uncharacterised protein family (UPF0128) | |
| PF03677 | UPF0137 | Uncharacterised protein family (UPF0137) | |
| PF03682 | UPF0158 | Uncharacterised protein family (UPF0158) | |
| PF03683 | UPF0175 | Uncharacterised protein family (UPF0175) | |
| PF03684 | UPF0179 | Uncharacterised protein family (UPF0179) | |
| PF03685 | UPF0147 | Uncharacterised protein family (UPF0147) | Q6LY05 |
| PF03686 | UPF0146 | Uncharacterised protein family (UPF0146) | O27081 |
| PF03687 | UPF0164 | Uncharacterised protein family (UPF0164) | |
| PF03691 | UPF0167 | Uncharacterised protein family (UPF0167) | |
| PF03695 | UPF0149 | Uncharacterised protein family (UPF0149) | Q5ZZD5 |
| PF03698 | UPF0180 | Uncharacterised protein family (UPF0180) | |
| PF03699 | UPF0182 | Uncharacterised protein family (UPF0182) | |
| PF03701 | UPF0181 | Uncharacterised protein family (UPF0181) | |
| PF03720 | UDPG_MGDP_dh_C | UDP-glucose/GDP-mannose dehydrogenase family, UDP binding domain | Q0P8H3 |
| PF03721 | UDPG_MGDP_dh_N | UDP-glucose/GDP-mannose dehydrogenase family, NAD binding domain | Q0P8H3 |
| PF03786 | UxuA | D-mannonate dehydratase (UxuA) | P24215 |
| PF03851 | UvdE | UV-endonuclease UvdE | Q4J9T1 |
| PF03981 | Ubiq_cyt_C_chap | Ubiquinol-cytochrome C chaperone | |
| PF03998 | Utp11 | Utp11 protein | B5VM59 |
| PF04003 | Utp12 | Dip2/Utp12 Family | P25635 |
| PF04050 | Upf2 | Up-frameshift suppressor 2 | Q9HAU5 |
| PF04115 | Ureidogly_lyase | Ureidoglycolate lyase | P59285 |
| PF04192 | Utp21 | Utp21 specific WD40 associated putative domain | Q06078 |
| PF04297 | UPF0122 | Putative helix-turn-helix protein, YlxM / p13 like | P67248 |
| PF04564 | U-box | U-box domain | Q9UMS4 |
| PF04615 | Utp14 | Utp14 protein | Q9BVJ6 |
| PF04869 | Uso1_p115_head | Uso1 / p115 like vesicle tethering protein, head region | P25386 |
| PF04871 | Uso1_p115_C | Uso1 / p115 like vesicle tethering protein, C terminal region | |
| PF04884 | UVB_sens_prot | Vitamin B6 photo-protection and homoeostasis domain | |
| PF05194 | UreE_C | UreE urease accessory protein, C-terminal domain | P50049 |
| PF05216 | UNC-50 | UNC-50 family | |
| PF05234 | UAF_Rrn10 | UAF complex subunit Rrn10 | P38204 |
| PF05250 | UPF0193 | Uncharacterised protein family (UPF0193) | |
| PF05254 | UPF0203 | Uncharacterised protein family (UPF0203) | O43715 |
| PF05255 | UPF0220 | Uncharacterised protein family (UPF0220) | |
| PF05256 | UPF0223 | Uncharacterised protein family (UPF0223) | Q9K9K7 |
| PF05348 | UMP1 | Proteasome maturation factor UMP1 | P38293 |
| PF05365 | UCR_UQCRX_QCR9 | Ubiquinol-cytochrome C reductase, UQCRX/QCR9 like | A0A1S3TQD2 |
| PF05473 | UL45 | UL45 protein, carbohydrate-binding C-type lectin-like | |
| PF05685 | Uma2 | Putative restriction endonuclease | Q04QG8 |
| PF05722 | Ustilago_mating | Ustilago B locus mating-type protein | |
| PF05727 | UPF0228 | Uncharacterised protein family (UPF0228) | |
| PF05728 | UPF0227 | Uncharacterised protein family (UPF0227) | O68216 |
| PF05743 | UEV | UEV domain | Q99816 |
| PF05822 | UMPH-1 | Pyrimidine 5'-nucleotidase (UMPH-1) | Q969T7 |
| PF05978 | UNC-93 | Ion channel regulatory protein UNC-93 | Q8VCW4 |
| PF06062 | UPF0231 | Uncharacterised protein family (UPF0231) | |
| PF06181 | Urate_ox_N | Urate oxidase N-terminal | |
| PF06233 | Usg | Usg-like family | |
| PF06427 | UDP-g_GGTase | UDP-glucose:Glycoprotein Glucosyltransferase | G0SB58 |
| PF06603 | UpxZ | UpxZ family of transcription anti-terminator antagonists | A7V9P0 |
| PF06782 | UPF0236 | Uncharacterised protein family (UPF0236) | |
| PF06783 | UPF0239 | Uncharacterised protein family (UPF0239) | |
| PF06784 | UPF0240 | Uncharacterised protein family (UPF0240) | |
| PF06785 | UPF0242 | Uncharacterised protein family (UPF0242) N-terminus | |
| PF06786 | UPF0253 | Uncharacterised protein family (UPF0253) | P0A8K7 |
| PF06788 | UPF0257 | Uncharacterised protein family (UPF0257) | |
| PF06790 | UPF0259 | Uncharacterised protein family (UPF0259) | |
| PF06792 | UPF0261 | Uncharacterised protein family (UPF0261) N-terminal domain | A7M6E7 |
| PF06793 | UPF0262 | Uncharacterised protein family (UPF0262) | |
| PF06794 | UPF0270 | Uncharacterised protein family (UPF0270) | Q9HYE3 |
| PF06862 | Utp25_C | Utp25, C-terminal domain | |
| PF07168 | Ureide_permease | Ureide permease | |
| PF07353 | Uroplakin_II | Uroplakin II | |
| PF07539 | UTP20_N | U3 small nucleolar RNA-associated protein 20, N-terminal | P35194 |
| PF07593 | UnbV_ASPIC | ASPIC and UnbV | |
| PF07702 | UTRA | UTRA domain | Q9K492 |
| PF08064 | UME | UME (NUC010) domain | P38111 |
| PF08297 | U3_snoRNA_assoc | U3 snoRNA associated | Q08492 |
| PF08449 | UAA | UAA transporter family | P40107 |
| PF08459 | UvrC_RNaseH_dom | UvrC RNAse H endonuclease domain | Q9RUN0 |
| PF08587 | UBA_2 | Ubiquitin associated domain (UBA) | O74536 |
| PF08594 | UPF0300 | Uncharacterised protein family (UPF0300) | |
| PF08625 | Utp13 | Utp13 specific WD40 associated domain | Q05946 |
| PF08640 | U3_assoc_6 | U3 small nucleolar RNA-associated protein 6 | Q9NYH9 |
| PF08694 | UFC1 | Ubiquitin-fold modifier-conjugating enzyme 1 | Q9Y3C8 |
| PF08864 | UPF0302 | UPF0302 domain | Q81SV3 |
| PF08941 | USP8_interact | USP8 interacting | Q8BH75 |
| PF08969 | USP8_dimer | USP8 dimerisation domain | O95630 |
| PF08997 | UCR_6-4kD | Ubiquinol-cytochrome C reductase complex, 6.4kD protein | P07552 |
| PF09138 | Urm1 | Urm1 (Ubiquitin related modifier) | G0SE11 |
| PF09145 | Ubiq-assoc | Ubiquitin-associated | Q06677 |
| PF09165 | Ubiq-Cytc-red_N | Ubiquinol-cytochrome c reductase 8 kDa, N-terminal | P13272 |
| PF09288 | UBA_3 | Fungal ubiquitin-associated domain | P21734 |
| PF09333 | unknown:not in list | | |
| PF09384 | UTP15_C | UTP15 C terminal | Q04305 |
| PF09416 | UPF1_Zn_bind | RNA helicase (UPF2 interacting domain) | P30771 |
| PF09720 | Unstab_antitox | Putative addiction module component | |
| PF09753 | Use1 | Membrane fusion protein Use1 | Q6CL08 |
| PF10293 | unknown:not in list | | |
| PF10305 | unknown:not in list | | |
| PF10347 | unknown:not in list | | |
| PF10351 | unknown:not in list | | |
| PF10359 | unknown:not in list | | |
| PF10395 | Utp8_b_propeller | Utp8, N-terminal beta propeller | P53276 |
| PF10399 | UCR_Fe-S_N | Ubiquitinol-cytochrome C reductase Fe-S subunit TAT signal | Q02762 |
| PF10408 | Ufd2P_core | Ubiquitin elongating factor core | P54860 |
| PF10441 | Urb2 | Urb2/Npa2 family | |
| PF10479 | unknown:not in list | | |
| PF10506 | USHBP1_PDZ-bd | Harmonin-binding protein USHBP1, PDZ-binding domain | |
| PF10571 | UPF0547 | Uncharacterised protein family UPF0547 | |
| PF10572 | UPF0556 | UPF0556 domain | Q969H8 |
| PF10573 | UPF0561 | Uncharacterised protein family UPF0561 | |
| PF10574 | UPF0552 | Arp2/3-interacting proteins Arpin | |
| PF10585 | UBA_E1_SCCH | Ubiquitin-activating enzyme, SCCH domain | P22515 |
| PF10596 | U6-snRNA_bdg | U6-snRNA interacting domain of PrP8 | Q6P2Q9 |
| PF10597 | U5_2-snRNA_bdg | U5-snRNA binding site 2 of PrP8 | Q6P2Q9 |
| PF10625 | UspB | Universal stress protein B (UspB) | |
| PF11094 | UL11 | Membrane-associated tegument protein | |
| PF11543 | UN_NPL4 | Nuclear pore localisation protein NPL4 | Q9VBP9 |
| PF11701 | UNC45-central | Myosin-binding striated muscle assembly central | G5EG62 |
| PF11703 | UPF0506 | UPF0506 | |
| PF11803 | UXS1_N | UDP-glucuronate decarboxylase N-terminal | |
| PF11807 | UstYa | Mycotoxin biosynthesis protein UstYa | |
| PF12220 | U1snRNP70_N | U1 small nuclear ribonucleoprotein of 70kDa MW N terminal | Q00916 |
| PF12344 | UvrB | Ultra-violet resistance protein B | P56981 |
| PF12397 | U3snoRNP10 | U3 small nucleolar RNA-associated protein 10 | Q9H583 |
| PF12436 | USP7_ICP0_bdg | ICP0-binding domain of Ubiquitin-specific protease 7 | Q93009 |
| PF12478 | UBAP2-Lig | UBAP2/protein lingerer | |
| PF12640 | UPF0489 | UPF0489 domain | D8G6F7 |
| PF13109 | unknown:not in list | | |
| PF13361 | UvrD_C | UvrD-like helicase C-terminal domain | A0A024LB08 |
| PF13423 | UCH_1 | Ubiquitin carboxyl-terminal hydrolase | P53010 |
| PF13502 | unknown:not in list | | |
| PF13538 | UvrD_C_2 | UvrD-like helicase C-terminal domain | P04993 |
| PF13980 | UPF0370 | Uncharacterised protein family (UPF0370) | |
| PF14075 | UBN_AB | Ubinuclein conserved middle domain | |
| PF14377 | UBM | Ubiquitin binding region | Q7Z6Z7 |
| PF14451 | Ub-Mut7C | Mut7-C ubiquitin | |
| PF14533 | USP7_C2 | Ubiquitin-specific protease C-terminal | Q93009 |
| PF14555 | UBA_4 | UBA-like domain | O35987 |
| PF14560 | Ubiquitin_2 | Ubiquitin-like domain | O13255 |
| PF14681 | UPRTase | Uracil phosphoribosyltransferase | Q59QT3 |
| PF14732 | UAE_UbL | Ubiquitin/SUMO-activating enzyme ubiquitin-like domain | Q9UBT2 |
| PF14776 | UNC-79 | Cation-channel complex subunit UNC-79 | Q9P2D8 |
| PF14814 | UB2H | Bifunctional transglycosylase second domain | P02919 |
| PF14836 | Ubiquitin_3 | Ubiquitin-like domain | P51784 |
| PF14982 | UPF0731 | UPF0731 family | |
| PF15086 | UPF0542 | Uncharacterised protein family UPF0542 | |
| PF15092 | UPF0728 | Uncharacterised protein family UPF0728 | |
| PF15114 | UPF0640 | Uncharacterised protein family UPF0640 | |
| PF15117 | UPF0697 | Uncharacterised protein family UPF0697 | |
| PF15135 | UPF0515 | Uncharacterised protein UPF0515 | |
| PF15136 | UPF0449 | Uncharacterised protein family UPF0449 | |
| PF15141 | UQCC3 | Ubiquinol-cytochrome-c reductase complex assembly factor 3 | |
| PF15435 | UNC119_bdg | UNC119-binding protein C5orf30 homologue | |
| PF15456 | Uds1 | Up-regulated During Septation | |
| PF15475 | UPF0444 | Transmembrane protein C12orf23, UPF0444 | |
| PF15744 | UPF0492 | Uncharacterized protein family UPF0492 | |
| PF15750 | UBZ_FAAP20 | Ubiquitin-binding zinc-finger | Q6NZ36 |
| PF15772 | UPF0688 | UPF0688 family | |
| PF15778 | UNC80_N | UNC80 N-terminal | Q8N2C7 |
| PF15823 | UPF0524 | UPF0524 of C3orf70 | |
| PF15827 | UPF0730 | UPF0730 unknown protein family | |
| PF15972 | Unpaired | Unpaired protein | |
| PF15990 | UPF0767 | UPF0767 family | |
| PF16195 | UBA2_C | SUMO-activating enzyme subunit 2 C-terminus | Q9UBT2 |
| PF16257 | UxaE | tagaturonate epimerase | |
| PF16455 | UBD | Ubiquitin-binding domain | Q8WUN7 |
| PF16534 | ULD | Ubiquitin-like oligomerisation domain of SATB | Q60611 |
| PF16577 | UBA_5 | UBA domain | Q64337 |
| PF16602 | USP19_linker | Linker region of USP19 deubiquitinase | |
| PF16674 | UCH_N | N-terminal of ubiquitin carboxyl-terminal hydrolase 37 | Q86T82 |
| PF16678 | UBA_HOIP | HOIP UBA domain pair | Q96EP0 |
| PF16909 | unknown:not in list | | |
| PF16910 | unknown:not in list | | |
| PF16975 | UPAR_LY6_2 | Ly6/PLAUR domain-containing protein 6, Lypd6 | Q8NI32 |
| PF17065 | UPF0669 | Putative cytokine, C6ORF120 | |
| PF17085 | UCMA | Unique cartilage matrix associated protein | |
| PF17094 | UPF0715 | Uncharacterised protein family (UPF0715) | |
| PF17217 | UPA | UPA domain | O08722 |
| PF17271 | Usher_TcfC | TcfC Usher-like barrel domain | |
| PF17391 | Urocanase_N | Urocanase N-terminal domain | A0A0Q9KFZ4 |
| PF17392 | Urocanase_C | Urocanase C-terminal domain | A0A0Q9KFZ4 |
| PF17638 | UL42 | HCMV UL42 | |
| PF17755 | UvrA_DNA-bind | UvrA DNA-binding domain | P9WQK7 |
| PF17757 | UvrB_inter | UvrB interaction domain | P30958 |
| PF17760 | UvrA_inter | UvrA interaction domain | P0A698 |
| PF17773 | UPF0176_N | UPF0176 acylphosphatase like domain | Q5ZRP2 |
| PF17809 | UPA_2 | UPA domain | P16157 |
| PF18031 | UCH_C | Ubiquitin carboxyl-terminal hydrolases | Q92560 |
| PF18036 | Ubiquitin_4 | Ubiquitin-like domain | Q8VIK1 |
| PF18037 | Ubiquitin_5 | Ubiquitin-like domain | Q9Y5A7 |
| PF18039 | UBA_6 | UBA-like domain | Q5D1E7 |
| PF18141 | UPF1_1B_dom | RNA helicase UPF1, 1B domain | Q92900 |
| PF18473 | Urease_linker | Urease subunit beta-alpha linker domain | P07374 |
| PF18792 | UspA1_rep | Ubiquitous surface protein adhesin repeat | Q9XD56 |
| PF19026 | UBA_HYPK | HYPK UBA domain | Q13765 |
| PF19424 | UNC80 | Protein UNC80 central region | Q8N2C7 |
| PF19718 | USP47_C | Ubiquitin carboxyl-terminal hydrolase 47 C-terminal | |
| PF19785 | UPF0738 | Family of unknown function (UPF0738) | |
| PF20180 | UQCC2_CBP6 | Complex III assembly factor UQCC2/CBP6 | |
| PF20262 | UNC80_C | Protein UNC80 C-terminal region | Q8N2C7 |
| PF20416 | UTP20 | U3 small nucleolar RNA-associated protein 20 domain | P35194 |
| PF20513 | UBact | Prokaryotic ubiquitin-like protein UBact | |
| PF20582 | UPF0758_N | UPF0758 N-terminal | |
| PF20695 | UbiD_N | 3-octaprenyl-4-hydroxybenzoate carboxy-lyase N-terminal domain | |
| PF20696 | UbiD_C | 3-octaprenyl-4-hydroxybenzoate carboxy-lyase C-terminal domain | |
| PF20867 | UVSSA_N | UVSSA N-terminal domain | |
| PF20908 | UfSP2_N | Ubiquitin-fold modifier 1 specific protease 2, N-terminal | |
| PF21115 | UBA_BRSK | BRSK1/2 UBA domain | |
| PF21219 | USH1C_N | Harmonin, N-terminal domain | |
| PF21235 | UBA_ARI1 | E3 ubiquitin-protein ligase ARIH1, UBA-like domain | |
| PF21241 | UvsW_N | DNA helicase UvsW, N-terminal | |
| PF21246 | Usp38-like_N | Ubiquitin carboxyl-terminal hydrolase 38-like, N-terminal domain | |
| PF21267 | UBAP-1_UBA2 | Ubiquitin-associated protein 1, UBA2 domain | |
| PF21290 | UBA_BIRC2-3 | BIRC2/3-like, UBA domain | |
| PF21594 | UBA_MELK | Maternal embryonic leucine zipper kinase, UBA domain | |
| PF21675 | unknown:not in list | | |
| PF21676 | unknown:not in list | | |
| PF21677 | unknown:not in list | | |
| PF21679 | unknown:not in list | | |
| PF21748 | UPF0150 | UPF0150-like | |
| PF21909 | USP_UIM_N | Ubiquitin-specific protease UIM domain | |
| PF22040 | U9-ORF | Secreted glycosylated protein U9-ORF | |
| PF22084 | UfSP_MPN_N | Ufm1 specific protease UfSP N-terminal MPN domain | |
| PF22542 | Utp8_C | Utp8, C-terminal | |
| PF22562 | UBA_7 | UBA-like domain | |
| PF22566 | UBA_8 | UBA-like domain | |
| PF22567 | UBA_9 | UBA-like domain | |
| PF22583 | UPF0425_C | UPF0425 C-terminal domain | |
| PF22866 | unknown:not in list | | |
| PF22893 | ULD_2 | Ubiquitin-like domain | |
| PF22900 | UCH_UBL1 | Ubiquitin carboxyl-terminal hydrolases, Ubiquitin-like 1 | |
| PF22916 | UTP25_NTPase-like | UTP25, NTP hydrolase-like domain | |
| PF22920 | UvrC_RNaseH | UvrC Ribonuclease H-like domain | |
| PF22932 | Ubiq_DUF_assoc | DUF569 associated ubiquitin-like domain | |
| PF22947 | ULD_3 | Leucine--tRNA ligase, ubiquitin-like domain | |
| PF22960 | UBR1-like_wing | E3 ubiquitin-protein ligase UBR1-like, winged-helix domain | |
| PF23009 | UBC_like | Ubiquitin conjugating domain-like | |
| PF23053 | UBA_N4BP1 | N4BP1, UBA-like domain | |
| PF23054 | UBA_N4BP1_C | N4BP1, C-terminal UBA domain | |
| PF23072 | unknown:not in list | | |
| PF23092 | Ubiquitin_6 | Neuron navigator 1-like, ubiquitin-like domain | |
| PF23099 | UTP20_C | Small subunit processome component 20 homolog, C-terminal | |
| PF23149 | UBA_Crd2 | Cdr2 UBA domain | |
| PF23164 | UBL_AVO1 | AVO1 ubiquitin-like domain | |
| PF23187 | UBX7_N | UBX7 N-terminal domain | |
| PF23189 | UPF0261_C | Uncharacterised protein family (UPF0261) C-terminal domain | |
| PF23195 | UBQLN1 | Ubiquilin-1-like domain | |
| PF23312 | UBA_SIK3 | Protein kinase SIK3 UBA domain | |
| PF23326 | UBL_UBAC1 | UBAC1 UBL-like domain | |
| PF23567 | Ubiquitin_IARS1 | Isoleucine--tRNA ligase, cytoplasmic, ubiquitin-like | |
| PF23603 | Ubiquitin_TPR1 | Telomere repeat-binding protein 1-like, ubiquitin-like domain | |
| PF23625 | UIM_2 | Ubiquitin interaction motif | |
| PF23640 | UPA_SH3BP4 | SH3BP4 UPA domain | |
| PF23656 | unknown:not in list | | |
| PF23659 | UFL1 | E3 UFM1-protein ligase 1-like domain | |
| PF23679 | UPA-FIIND | UPA-FIIND domain | |
| PF24079 | UBR4 | E3 ubiquitin-protein ligase UBR4-like domain | |
| PF24160 | UVB_sens_C | Root UVB sensitive protein, C-terminal | |
| PF24543 | Usp-48 | Usp-48 domain | |
| PF24559 | UBA_RAD5A | DNA repair protein RAD5A UBA domain | |
| PF24696 | UGSC | UGSC family | |
| PF24767 | UBA_At5g58720 | At5g58720 UBA-like domain | |
| PF24779 | UTP23_sensor | UTP23 sensor motif | |
| PF24842 | UFD1_N2 | Ubiquitin fusion degradation protein UFD1, N-terminal subdomain 2 | |