F-box domain superfamily; This short domain is commonly found at the N-terminus of various proteins, and typically co-occurs with one or more other conserved domains or motifs, such as leucine rich repeats, WD40 repeats, kelch, tub, spry, and others. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression. One of the best researched roles of F-box proteins is their participation in SCF (Skp1-Cul1-F-box protein), a multi-protein complex that functions as a ubiquitin E3 ligase, where the role of the F-box protein is to recruit target substrates. Gene families containing the F-box are found greatly expanded in narrow taxonomic lineages, such as flowering plants and nematodes. In this hierarchical classification, many of the subfamilies are named according to their domain architectures.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 171543844  18 LTKLPPELLVQVLSHVPPRALVTRCRPVCRAWRDLVDGPSIWLLQLAR 65
Cdd:cd22169    1 LSLLPEELLLLVLSHVPARTLVTRCRLVCRDWRDLVDGPTLWKLKCER 48

F-box domain found in F-box only protein 17 (FBXO17), F-box only protein 27 (FBXO27) and similar proteins; This subfamily includes FBXO17 and FBXO27. FBXO17 is also called FBX17, F-box only protein 26 (FBX26/FBXO26), or FBG4, while FBXO27 is also called FBX27, or F-box/G-domain protein 5. FBXO17 and FBXO27 are the substrate-recognition components of SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complexes. They can recognize and bind denatured glycoproteins, which are modified with complex-type oligosaccharides. FBXO17 also recognizes sulfated glycans but does not bind high-mannose glycoproteins. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 171543844  18 LTKLPPELLVQVLSHVPPRALVTRCRPVCRAWRDLVDGPSIWLLQLAR 65
Cdd:cd22169    1 LSLLPEELLLLVLSHVPARTLVTRCRLVCRDWRDLVDGPTLWKLKCER 48

A Receptor for Ubiquitination Targets;

                           10        20        30
                   ....*....|....*....|....*....|....*....
gi 171543844    21 LPPELLVQVLSHVPPRALVtRCRPVCRAWRDLVDGPSIW 59
Cdd:smart00256   1 LPDEILEEILSKLDPKDLL-RLRKVSRKWRSLIDSHDFW 38

F-box domain found in F-box only protein 17 (FBXO17), F-box only protein 27 (FBXO27) and similar proteins; This subfamily includes FBXO17 and FBXO27. FBXO17 is also called FBX17, F-box only protein 26 (FBX26/FBXO26), or FBG4, while FBXO27 is also called FBX27, or F-box/G-domain protein 5. FBXO17 and FBXO27 are the substrate-recognition components of SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complexes. They can recognize and bind denatured glycoproteins, which are modified with complex-type oligosaccharides. FBXO17 also recognizes sulfated glycans but does not bind high-mannose glycoproteins. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 171543844  18 LTKLPPELLVQVLSHVPPRALVTRCRPVCRAWRDLVDGPSIWLLQLAR 65
Cdd:cd22169    1 LSLLPEELLLLVLSHVPARTLVTRCRLVCRDWRDLVDGPTLWKLKCER 48

F-box domain found in F-box only proteins FBXO6, FBXO44 and similar proteins; This subfamily includes FBXO6 and FBXO44. FBXO6, also called FBX6, F-box protein that recognizes sugar chains 2 (FBS2), or F-box/G-domain protein 2 (FBG2), is a substrate-recognition component of SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complexes. It is involved in the endoplasmic reticulum-associated degradation pathway (ERAD) for misfolded lumenal proteins, by recognizing and binding sugar chains on unfolded glycoproteins that are retro-translocated into the cytosol and promoting their ubiquitination and subsequent degradation. FBXO6 can recognize and bind denatured glycoproteins, which are modified with not only high-mannose but also complex-type oligosaccharides. It also recognizes sulfated glycans. FBXO6 is involved in DNA damage response by specifically recognizing activated CHEK1 (phosphorylated on 'Ser-345'), promoting its ubiquitination and degradation. FBXO44, also called FBXO6A, FBX44, or F-box/G-domain protein 3 (FBG3), is a substrate-recognition component of an SCF-type E3 ubiquitin ligase complex. It interacts with SKP1 and CUL1. FBXO44 mediates BRCA1 ubiquitination and degradation. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30
                 ....*....|....*....|....*....|....*....
gi 171543844  21 LPPELLVQVLSHVPPRALVTRCRPVCRAWRDLVDGPSIW 59
Cdd:cd22168    7 LPEDVLLEILSLVPARDLILSCRLVCSRWRDLVDLPTLW 45

F-box-like; This is an F-box-like family.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 171543844   18 LTKLPPELLVQVLSHVPPRALVtRCRPVCRAWRDLVDGPSIW 59
Cdd:pfam12937   1 LSSLPDEILLQIFSYLDPKDLL-RLALVCRRWRELASDDSLW 41

F-box domain; This domain is approximately 50 amino acids long, and is usually found in the N-terminal half of a variety of proteins. Two motifs that are commonly found associated with the F-box domain are the leucine rich repeats (LRRs; pfam00560 and pfam07723) and the WD repeat (pfam00400). The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 171543844   18 LTKLPPELLVQVLSHVPPRALVtRCRPVCRAWRDLVDGPSIWLL 61
Cdd:pfam00646   1 LLDLPDDLLLEILSRLDPKDLL-RLSLVSKRWRSLVDSLKLWKK 43

F-box domain found in F-box/LRR-repeat protein 5 (FBXL5) and similar proteins; FBXL5, also called F-box and leucine-rich repeat protein 5, F-box protein FBL4/FBL5, or p45SKP2-like protein, is the substrate-recognition component of an SCF (SKP1-cullin-F-box) protein ligase complex that plays a central role in iron homeostasis by promoting the ubiquitination and subsequent degradation of IREB2/IRP2. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 171543844  18 LTKLPPELLVQVLSHVPPRALvTRCRPVCRAWRDLVDGPSIW 59
Cdd:cd22118    1 ISSLPPEIMLKIFSYLNPQDL-CRCAQVCTKWSQLARDGSLW 41

F-box domain found in F-box only protein 31 (FBXO31) and similar proteins; FBXO31, also called FBX31, or FBXO14, is a component of an SCF (SKP1-cullin-F-box) protein ligase complex that plays a central role in G1 arrest following DNA damage. It specifically recognizes phosphorylated cyclin-D1 (CCND1), promoting its ubiquitination and degradation by the proteasome, resulting in G1 arrest. FBXO31 may act as a tumor suppressor. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 171543844  18 LTKLPPELLVQVLSHVPPRALVTRCRpVCRAWRDLVDGPSIW 59
Cdd:cd22102    1 ILDLPPELLVEIFSSLPGTDLPSLAQ-VCKKFREILNTDTIW 41

F-box domain found in F-box/LRR-repeat protein 6 (FBXL6) and similar proteins; FBXL6, also called F-box and leucine-rich repeat protein 6, or F-box protein FBL6 (FBL6A), is the substrate-recognition component of an SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 171543844  20 KLPPELLVQVLSHV-----PPRALVTRCRpVCRAWRDLVDGPSIW 59
Cdd:cd22119    3 RLPPEILVKIFQFAvategAVPLLCRLSR-VCRLWREVALDPSLW 46

F-box domain found in F-box only protein 18 (FBXO18) and similar proteins; FBXO18, also called FBX18, or F-box DNA helicase 1 (FBH1), is a 3'-5' DNA helicase and the substrate-recognition component of the SCF(FBH1) E3 ubiquitin ligase complex that plays a key role in response to stalled/damaged replication forks. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 171543844  18 LTKLPPELLVQVLSHVPPRALVTRCRPVCRAWRDLVDGPSI 58
Cdd:cd22095    2 IQQLPEELLRNIFAFLPAEDLYQNISLVCRHWRDIVSDPLF 42

F-box domain found in F-box only protein 1 (FBXO1) and similar proteins; FBXO1, also called FBX1, or cyclin-F, is a substrate-recognition component of an SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of CP110 during G2 phase, thereby acting as an inhibitor of centrosome reduplication. It is the largest among all cyclins and oscillates in the cell cycle like other cyclins. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 171543844  18 LTKLPPELLVQVLSHVPPRALVTrCRPVCRAWRDLVDG-PSIW 59
Cdd:cd22082    2 LWSLPEEVLLHILKGLPIKDLLN-MRAVHSRFKDLIDSnPSLW 43

F-box domain found in F-box/LRR-repeat protein 2 (FBXL2), F-box/LRR-repeat protein 20 (FBXL20) and similar proteins; The family includes FBXL2 and FBXL30. FBXL2, also called F-box and leucine-rich repeat protein 2, or F-box protein FBL2/FBL3, is a calcium-activated substrate-recognition component of an SCF (SKP1-cullin-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Unlike many F-box proteins, FBXL2 does not seem to target phosphodegron within its substrates but rather calmodulin-binding motifs and is thereby antagonized by calmodulin. FBXL20, also called SCRAPPER, F-box and leucine-rich repeat protein 20, or F-box/LRR-repeat protein 2-like, is a component of a synapse-localized SCF-type E3 ubiquitin ligase which regulates neural transmission. It is widely expressed in the central nervous system and plays an important role in the ubiquitin-dependent degradation of regulating synaptic membrane exocytosis 1 (RIM1), which is an important factor in the release of synaptic vesicles. It may also mediate the ubiquitin degradation of E-cadherin resulting in an increased invasive ability of malignant cells. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 171543844  20 KLPPELLVQVLSHVPPRALVtRCRPVCRAWRDL-VDGpSIW 59
Cdd:cd22115    6 KLPKELLLRIFSFLDVVTLC-RCAQVSKYWNVLaLDG-SNW 44

F-box domain found in F-box only protein 24 (FBXO24) and similar proteins; FBXO24, also called FBX24, is the substrate-recognition component of an SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex. It recognizes deacetylated nucleoside diphosphate kinase A (NDPK-A) to enhance its degradation. The F-box domain has a role in mediating protein-protein interactions in a variety of contexts, such as polyubiquitination, transcription elongation, centromere binding and translational repression.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|
gi 171543844  21 LPPELLVQVLSHVPPRALVtRCRPVCRAWRDLVDGPSIWL 60
Cdd:cd22098    5 LPPEILDRIISFLPVKDIV-SLGQTCRYFHEVCNSEAVWR 43