Protein
Actin cross-linking toxin VgrG1
Organism
Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961)
Function
Actin-directed toxin that catalyzes the covalent cross-linking of host cytoplasmic monomeric actin. Mediates the cross-link between 'Lys-50' of one monomer and 'Glu-270' of another actin monomer, resulting in formation of highly toxic actin oligomers that cause cell rounding (PubMed:17873062, PubMed:20150509). The toxin can be highly efficient at very low concentrations by acting on formin homology family proteins: toxic actin oligomers bind with high affinity to formins and adversely affect both nucleation and elongation abilities of formins, causing their potent inhibition in both profilin-dependent and independent manners (By similarity). Acts as an acid--amino-acid ligase that transfers the gamma-phosphoryl group of ATP to the 'Glu-270' actin residue, resulting in the formation of an activated acyl phosphate intermediate. This intermediate is further hydrolyzed and the energy of hydrolysis is utilized for the formation of the amide bond between actin subunits (By similarity).
Sequence
MATLAYSIEVEGLEDETLVVRGFHGQESLSNSVFLGQACYGFRYEVQLASRVSNLTAEQMVDKRAELKLYRNSQLVQRVHGIVRAFSQGDIGHHHTFYQLTLVPALERLSLRHNSRIFQKQTVPEILSILLQEMGINDYAFALKRDGVQREFCVQYRESDIDFLHRLAAEEGLVYSFVHEAGKHTLYFSDASDSLSKLPEPIPYNALVGGAIDTPYIHGLTYRTQAEVSEVQLKDYSFKKPAYSFLQTVQGTELDYQQTRYQHFDAPGRYKDDVNGAAFSQIRLDYLRRHAHTATGQSNEPLLRAGYKFDLQEHLDPAMNRDWVVVSINHQGEQPQALQEDGGSGATTYSNQFSLIPGHLHWRAEPQPKPQVDGPMIATVVGPEGEEIFCDEHGRVKIHFPWDRYSNGNEQSSCWVRVSQGWAGSQYGFIAIPRIGHEVIVEFLNGDPDQPIITGRTYHATNTPPYTLPEHKTKTVLRTETHQGEGFNELSFEDQAGKEQIYLHAQKDFDGLIENDHTTVIRHDHHLTVENDQFTQIKHNQHLTVEWESREAVTGEQVLSIEGSLHVKTGKVWVNEAGTEIHVKAGQKVVIEAGSEITVKAGGSFVKVDPAGVHLSGALVNLNSGGSAGSGSGFGGAMPALPGGLEPAVALAPPQTISYQALLQAEQANVPAVKVCPLAAQEATPAVNSITPPPPPPIAPPMAPPQPIMNPQPTANAQPNLGRSTKATPDFPTHFPKSSIGIENELAGLVVAMPANSAQKFGYVKSAQGDALFMLTKDMNQGSYQRPPSLQDGKNYQNWQTHTVELVSYPCEMDDKAAVETRKQAMLWLATHFTTHIDQSNHQPLAPIQSEDGRFVIEITNAKHVIAAGNGISAESQGQTITMTPSGQQATVGVAAKGFGTSATPELRLLESAPWYQKSLKSQFASLTSAENLDDKELAANVFAYLTSIYLKTAELAKKFGIYINEWDPMSEQITPNANGLTDPKVKNAWEILPRTKPSKIVEILSKSDAKAVMKHIKPQLQSRYSESLSKNVFQYFQDGGEVAGHGINNATVGDKHSPELAILFEFRTVPNELQSYLPKTESTTKSEVKLLDQFDPMKRKTVIQQVESLVQNSGDAFDKWYQSYRDSMNQPPVKNAKKIASANQKAQWVKEHNPQEWQRIIA