Putative xylosyltransferase genes in Trichomonas vaginalis

Protein xylosyltransferases are the group of enzymes which are involved in transferring xylose from UDP-d-xylose to serine residue in a protein. These enzymes are commonly found in multicellular organisms and in some unicellular organisms. Previously we had identified the xylosyltransferase (XT) genes in EST sequence of a unicellular organism Trichomonas vaginalis through in silico approach based on the sequence homology. To corroborate if these genes are putative XT genes, we designed a workflow based on the sequence characteristics of xylosyltransferase, to verify if any of the putative XT gene sequences have sequence motifs. The XT genes in T. vaginalis predicted by Hidden Markov Model (HMM) were further analyzed with PfamHMM to identify if each putative sequence belongs to a known protein family, with TMHMM to examine whether the predicted XTs are Golgi xylosyltransferases and with MEME to find out the conserved motifs. The results confirmed our earlier study that these XTs are related to N-linked XTs in plants. To confirm the in silico results further, we analyzed the N-linked glycans of T. vaginalis and the empirical data also confirmed the computational analysis.