Effect of PKD1L1 Mutation on its Interaction with PKD2 to Cause Situs Inversus Totalis

Situs inversus totalis (SIT) is a rare homozygous recessive disease caused by the mutation in PKD1L1, which is required for normal interaction with PKD2 and leads to different complications such as respiratory disorders, brain disorders and even obesity. The present study was designed to find out the mutational effect on the binding of PKD2 with mutated PKD1L1, which leads to SIT. The three-dimensional (3D) structure of wild type and mutated PKD1L1 was predicted with > 90% confidence using different online tools. The different online tools that were employed were SWISS-MODEL, Phyre2 (normal & intensive) and i-TASSER. To compute the physiochemical properties of PKD1L1 (wild & mutated) and PKD2 in silico approaches were employed using the ExPASy ProtParam tool. Physicochemical properties such as molecular weight, isoelectric point, the total number of negatively and positively charged residues, extinction coefficient, half-life, instability and aliphatic index, grand average of hydropathicity, and amino acid percentage were calculated. A lot of variability was observed in these parameters among PKD1L1 and PKD2, which accounted for diversification in their functional properties. The theoretical pI points showed that PKD1L1 (whole) is more basic with 6.64 pI compared to its first chain TOPO_DOM (amino acids from 1–1748) has a pI of 5.62 which means it is basic while PKD2 have the lowest pI point of 5.34. Docking was performed using the PatchDock and ClusPro online tools.