Protein: Botulinum neurotoxin type F (BoNT/F) (Bontoxilysin-F) [Cleaved into: Botulinum neurotoxin F light chain (LC) (EC 3.4.24.69); Botulinum neurotoxin F heavy chain (HC)] (P30996)
Organism: Clostridium botulinum
Function: Botulinum toxin causes flaccid paralysis by inhibiting neurotransmitter (acetylcholine) release from the presynaptic membranes of nerve terminals of the eukaryotic host skeletal and autonomic nervous system, with frequent heart or respiratory failure. Precursor of botulinum neurotoxin F which may have 2 coreceptors; complex polysialylated gangliosides found on neural tissue and specific membrane-anchored proteins found in synaptic vesicles. Receptor proteins are exposed on host presynaptic cell membrane during neurotransmitter release, when the toxin heavy chain (HC) binds to them. Upon synaptic vesicle recycling the toxin is taken up via the endocytic pathway. When the pH of the toxin-containing endosome drops a structural rearrangement occurs so that the N-terminus of the HC forms pores that allows the light chain (LC) to translocate into the cytosol. Once in the cytosol the disulfide bond linking the 2 subunits is reduced and LC cleaves its target protein on synaptic vesicles, preventing their fusion with the cytoplasmic membrane and thus neurotransmitter release (By similarity). Whole toxin only has protease activity after reduction, which releases LC. Requires complex eukaryotic host polysialogangliosides for full neurotoxicity (By similarity). It is not clear whether a synaptic vesicle protein acts as its receptor; there is evidence for and against SV2 fulfilling this function (By similarity).
Subcellular location: [Botulinum neurotoxin type F]: Secreted {ECO:0000250|UniProtKB:P0DPI0}.; SUBCELLULAR LOCATION: [Botulinum neurotoxin F light chain]: Secreted {ECO:0000250|UniProtKB:P0DPI0}. Host cytoplasm, host cytosol {ECO:0000305|PubMed:8175689, ECO:0000305|PubMed:8505288}.; SUBCELLULAR LOCATION: [Botulinum neurotoxin F heavy chain]: Secreted {ECO:0000250|UniProtKB:P0DPI0}. Host synapse, host presynaptic cell membrane {ECO:0000305}. Host cytoplasmic vesicle, host secretory vesicle, host synaptic vesicle membrane {ECO:0000250|UniProtKB:P0DPI0}; Multi-pass membrane protein {ECO:0000305}.
Interaction partners:
Sequence:
MPVAINSFNYNDPVNDDTILYMQIPYEEKSKKYYKAFEIMRNVWIIPERNTIGTNPSDFDPPASLKNGSSAYYDPNYLTTDAEKDRYLKTTIKLFKRINSNPAGKVLLQEISYAKPYLGNDHTPIDEFSPVTRTTSVNIKLSTNVESSMLLNLLVLGAGPDIFESCCYPVRKLIDPDVVYDPSNYGFGSINIVTFSPEYEYTFNDISGGHNSSTESFIADPAISLAHELIHALHGLYGARGVTYEETIEVKQAPLMIAEKPIRLEEFLTFGGQDLNIITSAMKEKIYNNLLANYEKIATRLSEVNSAPPEYDINEYKDYFQWKYGLDKNADGSYTVNENKFNEIYKKLYSFTESDLANKFKVKCRNTYFIKYEFLKVPNLLDDDIYTVSEGFNIGNLAVNNRGQSIKLNPKIIDSIPDKGLVEKIVKFCKSVIPRKGTKAPPRLCIRVNNSELFFVASESSYNENDINTPKEIDDTTNLNNNYRNNLDEVILDYNSQTIPQISNRTLNTLVQDNSYVPRYDSNGTSEIEEYDVVDFNVFFYLHAQKVPEGETNISLTSSIDTALLEESKDIFFSSEFIDTINKPVNAALFIDWISKVIRDFTTEATQKSTVDKIADISLIVPYVGLALNIIIEAEKGNFEEAFELLGVGILLEFVPELTIPVILVFTIKSYIDSYENKNKAIKAINNSLIEREAKWKEIYSWIVSNWLTRINTQFNKRKEQMYQALQNQVDAIKTAIEYKYNNYTSDEKNRLESEYNINNIEEELNKKVSLAMKNIERFMTESSISYLMKLINEAKVGKLKKYDNHVKSDLLNYILDHRSILGEQTNELSDLVTSTLNSSIPFELSSYTNDKILIIYFNRLYKKIKDSSILDMRYENNKFIDISGYGSNISINGNVYIYSTNRNQFGIYNSRLSEVNIAQNNDIIYNSRYQNFSISFWVRIPKHYKPMNHNREYTIINCMGNNNSGWKISLRTVRDCEIIWTLQDTSGNKENLIFRYEELNRISNYINKWIFVTITNNRLGNSRIYINGNLIVEKSISNLGDIHVSDNILFKIVGCDDETYVGIRYFKVFNTELDKTEIETLYSNEPDPSILKNYWGNYLLYNKKYYLFNLLRKDKYITLNSGILNINQQRGVTEGSVFLNYKLYEGVEVIIRKNGPIDISNTDNFVRKNDLAYINVVDRGVEYRLYADTKSEKEKIIRTSNLNDSLGQIIVMDSIGNNCTMNFQNNNGSNIGLLGFHSNNLVASSWYYNNIRRNTSSNGCFWSSISKENGWKE