Bioinformatic Analyses of the KX Blood-Group Antigen (KXA) Family and its inclusion in the Transporter-Opsin-G Protein-coupled Receptor (TOG) Superfamily
A bioinformatic characterization of the KX Blood- Group Antigen (KXA) Family has been conducted. This family includes the XK-related protein 8 which has recently been shown to function as a phospholipid flippase (Suzuki et al, 2013). This however, may not be its primary function. Multiple alignments, phylogenetic trees, and sequence analyses allowed me to characterize the KXA Family, revealing 17 primary clusters. Also, using average hydropathy, amphipathicity, and similarity plots, I was able to show that the members of this family possess on average 9 transmembrane helices (TMSs). Although, previous work has mostly been done with animal proteins, I demonstrate that homologs can be found in plants and ciliates. Furthermore, I show that the KXA family is a member of an established superfamily (TOG) of proteins having transport, light reception, electron flow, and G-protein receptor functions.