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
                  ....*....|....*....|....*...
gi 2020805637   8 EQLPEEVLALIFRHLPLRDRATASRVCR 35
Cdd:cd22121     1 NALPEEILVHIFRHLSLRDRYAAAQVCK 28

F-box domain found in F-box/LRR-repeat protein 8 (FBXL8) and similar proteins; FBXL8, also called F-box and leucine-rich repeat protein 8, or F-box protein FBL8, 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
                  ....*....|....*....|....*...
gi 2020805637   8 EQLPEEVLALIFRHLPLRDRATASRVCR 35
Cdd:cd22121     1 NALPEEILVHIFRHLSLRDRYAAAQVCK 28

Leucine-rich repeat domain of FBXL3 and related proteins; F-box/LRR-repeat proteins are part of Skp1-Cul1-F-box-protein (SCF) ubiquitin ligase complexes. They contain an F-Box, which binds to the core complex component SKP and a leucine-rich repeat (LRR) domain which gives substrate binding specificity. FBXL3 (F-box and leucine rich repeat protein 3) and FBXL21 have been shown to bind CRY1 repressors and are involved in regulation of circadian clock.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2020805637 136 SCALRHLDLRRLPftLDDA-LVLQASRGCPELRSLFLNNCTLVgsvSPDSVLELLKACPRLRALGLHLASLSGTALQMLA 214
Cdd:cd23951    93 SSSLSSLAIDDTP--VDDPsLQTLASSSSDTLELLKMKSCPRV---SPRGILAVADHCQHLRELSLNYHLLSDDLLLALS 167

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2020805637 215 APDRAPFAHLALRCACPEDVRAP--SLPEEDWAAVRRRHPSLVVELELEpALPDESVTRVLQPAVPVAAL 282
Cdd:cd23951   168 SEEHVRLEHLRIDVVSENDGPMPlhQISKESWDALIKHSPDVNLVMYFF-VLEDEDFDPFFRSYTPVTHL 236

F-box/LRR-repeat protein 18, LRR; This entry represents the leucine-rich repeats (LRR) from F-box/LRR repeat protein 18 (also known as F-box and leucine-rich repeat protein 18, FBXL18), associated with F-box domains. This protein is the substrate-recognition component of the SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex through its F-box and the LRR motifs mediate the protein-protein interactions required for the binding of the specific substrates by SCFs complexes.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2020805637 139 LRHLDLRRLPFTLDDALVLQASRGCPELRSLFLNNCTLVGSVS-PDSVLELLKACPRLRALGLHLASLSGTA 209
Cdd:pfam19729 452 LRRLTLAQLPGILTGSGLVQIGLQCQDLQVLSLANLGMLGKVNyMPALCEMLKHCKQLKDLRLEQPYFSANA 523

F-box domain found in F-box/LRR-repeat protein 8 (FBXL8) and similar proteins; FBXL8, also called F-box and leucine-rich repeat protein 8, or F-box protein FBL8, 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
                  ....*....|....*....|....*...
gi 2020805637   8 EQLPEEVLALIFRHLPLRDRATASRVCR 35
Cdd:cd22121     1 NALPEEILVHIFRHLSLRDRYAAAQVCK 28

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

                          10        20
                  ....*....|....*....|....*...
gi 2020805637   8 EQLPEEVLALIFRHLPLRDRATASRVCR 35
Cdd:pfam12937   2 SSLPDEILLQIFSYLDPKDLLRLALVCR 29

Leucine-rich repeat domain of FBXL3 and related proteins; F-box/LRR-repeat proteins are part of Skp1-Cul1-F-box-protein (SCF) ubiquitin ligase complexes. They contain an F-Box, which binds to the core complex component SKP and a leucine-rich repeat (LRR) domain which gives substrate binding specificity. FBXL3 (F-box and leucine rich repeat protein 3) and FBXL21 have been shown to bind CRY1 repressors and are involved in regulation of circadian clock.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2020805637 136 SCALRHLDLRRLPftLDDA-LVLQASRGCPELRSLFLNNCTLVgsvSPDSVLELLKACPRLRALGLHLASLSGTALQMLA 214
Cdd:cd23951    93 SSSLSSLAIDDTP--VDDPsLQTLASSSSDTLELLKMKSCPRV---SPRGILAVADHCQHLRELSLNYHLLSDDLLLALS 167

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2020805637 215 APDRAPFAHLALRCACPEDVRAP--SLPEEDWAAVRRRHPSLVVELELEpALPDESVTRVLQPAVPVAAL 282
Cdd:cd23951   168 SEEHVRLEHLRIDVVSENDGPMPlhQISKESWDALIKHSPDVNLVMYFF-VLEDEDFDPFFRSYTPVTHL 236

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
                  ....*....|....*....|....*...
gi 2020805637   8 EQLPEEVLALIFRHLPLRDRATASRVCR 35
Cdd:pfam00646   2 LDLPDDLLLEILSRLDPKDLLRLSLVSK 29

F-box/LRR-repeat protein 18, LRR; This entry represents the leucine-rich repeats (LRR) from F-box/LRR repeat protein 18 (also known as F-box and leucine-rich repeat protein 18, FBXL18), associated with F-box domains. This protein is the substrate-recognition component of the SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex through its F-box and the LRR motifs mediate the protein-protein interactions required for the binding of the specific substrates by SCFs complexes.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2020805637 139 LRHLDLRRLPFTLDDALVLQASRGCPELRSLFLNNCTLVGSVS-PDSVLELLKACPRLRALGLHLASLSGTA 209
Cdd:pfam19729 452 LRRLTLAQLPGILTGSGLVQIGLQCQDLQVLSLANLGMLGKVNyMPALCEMLKHCKQLKDLRLEQPYFSANA 523

F-box domain found in F-box/LRR-repeat protein 3 (FBXL3), F-box/LRR-repeat protein 21 (FBXL21) and similar proteins; FBXL3, also called F-box and leucine-rich repeat protein 3A, or F-box/LRR-repeat protein 3A, is the substrate-recognition component of the SCF(FBXL3) E3 ubiquitin ligase complex that mainly acts in the nucleus and mediates ubiquitination and subsequent degradation of CRY1 and CRY2, and thus, is involved in circadian rhythm function. It plays a key role in the maintenance of both the speed and the robustness of the circadian clock oscillation. FBXL21, also called F-box and leucine-rich repeat protein 21, F-box and leucine-rich repeat protein 3B, or F-box/LRR-repeat protein 3B, is the substrate-recognition component of the SCF(FBXL21) E3 ubiquitin ligase complex that mainly acts in the cytosol and mediates ubiquitination of CRY proteins (CRY1 and CRY2), leading to CRY protein stabilization, and thus, is also involved in circadian rhythm function. It plays regulates the oscillation of the circadian clock through ubiquitination and stabilization of cryptochromes. 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
                  ....*....|....*....|....*.
gi 2020805637  10 LPEEVLALIFRHLPLRDRATASRVCR 35
Cdd:cd22116     5 LPSDIILHIFQYLPLLDRAHASLVCR 30

F-box domain found in F-box/WD repeat-containing protein 4 (FBXW4) and similar proteins; FBXW4, also called dactylin, or F-box and WD-40 domain-containing protein 4, probably recognizes and binds to some phosphorylated proteins and promotes their ubiquitination and degradation. It is likely to be involved in key signaling pathways crucial for normal limb development. It may participate in Wnt signaling and act as a novel tumor suppressor that regulates important cellular processes. 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 2020805637   9 QLPEEVLALIFRHLPLRDRATASRVCRAWAAAATCSAVW 47
Cdd:cd20090     4 DLPDDLLFLIFSYLDPASLGRLSQVCRRLYRLISRDAVW 42