Journal: Toxins
Article Title: Phylogenetic Analysis of Filifactor alocis Strains Isolated from Several Oral Infections Identified a Novel RTX Toxin, FtxA
doi: 10.3390/toxins12110687
Figure Lengend Snippet: ( A ) Overlapping conserved domains in the FtxA protein sequence, deduced using InterPro. The C-terminal portion displays homology to the Hemolysin-type calcium binding-related domain (IPR010566), and the serralysin-like metalloprotease superfamily (IPR011049), and contains repeats-in-toxins (RTX) calcium-binding nonapeptide repeats (IPR001343), and Hemolysin-type calcium-binding conserved sites (IPR018511). ( B ) One archetypal RTX gene cluster ( hlyCABD ) encodes the E. coli alpha-hemolysin, HlyA. HlyA is synthesized as an inactive protoxin, ProHlyA, which is post-translationally activated in two steps, first via HlyC-directed acylation in the cytoplasm, and then by binding Ca 2+ in the extracellular medium . The cyaE gene of B. pertussis encodes a homologue to E. coli tolC and plays a critical role in the secretion of CyaA . We identified no equivalent to an HlyC-homologue in the F. alocis genomes. The hypothetical protein encoded upstream of ftxA exhibits no apparent homology to hlyC or to other known proteins.
Article Snippet: We here aimed to perform phylogenetic analysis of a genome-sequenced F. alocis type strain (ATCC 35896; CCUG 47790), as well as nine clinical oral strains that we have independently isolated and sequenced, for identification and deeper characterization of novel genomic elements of virulence in this species.
Techniques: Sequencing, Binding Assay, Synthesized