Wolbachia WSP typing
The Wolbachia surface protein, WSP (wMel locus WD_1063), represents an additional marker for strain typing and it is not part of the MLST scheme. Use of wsp is analogous to the use of antigens for serotyping of pathogenic bacteria.
In addition to the MLST allelic profile, each strain can be further characterized based on the amino acid motifs of the four hypervariable regions (HVRs) of its WSP sequence. A relatively conserved set of amino acid motifs are present at each of the four HVRs, with shuffling of HVR motifs among strains (Baldo et al. 2005). Each WSP amino acid sequence (amino acid range with respect to wMel sequence is 52-222) is partitioned into four consecutive sections whose breakpoints fall within conserved regions between the hypervariable regions: HVR1 (amino acid range 52-84), HVR2 (85-134), HVR3 (135-185), HVR4 (186-222). Each section encompasses one of the four HVR motifs and a portion of the two conserved flanking regions. For simplicity we refer to each section as an HVR.
Each unique wsp nucleotide allele and each unique HVR amino acid sequence are given a number. Since the majority of amino acid changes among WSP sequences occur at the four HVRs, these motifs can be used as a signature for discrimination of the different WSP protein types. This method can also be used to readily detect allele shuffling based on unique identifiers for each HVR.
The database is organized into five distinct tables containing respectively:
- wsp nucleotide sequences (bp 61-573 respect to wMel)
- hvr1 amino acid sequences
- hvr2 amino acid sequences
- hvr3 amino acid sequences
- hvr4 amino acid sequences