Evolutionary and Structural Analyses of Toll-Like Receptors 7 and 8 of Himalayan Kumaon Cattle and Goat

Abstract

Toll-like receptors (TLRs) are pattern recognition receptors that are critical for the functions of the host innate immunity. This study reports complete coding sequences of TLR-7 and TLR-8 of cattle and goat of Himalayan Kumaon (HK) region. Further, predicted 26 leucine rich repeats (LRRs), two terminal LRR modules and putative common and differential ligand binding amino acids in TLR-7 and -8 of ruminants. The differential ligand binding amino acids between TLR-7 and TLR-8 of HK-cattle were Val396, Arg422, Val513, Asp538 and Val566 in TLR-8; Thr406, Lys432, Thr533, Leu558 and Ile586 in TLR-7. Codon selection analysis revealed co-localization of positively selected codons 377 and 408 of cattle, and 402 and 859 of goat with already reported SNPs in ruminants. The comparative analysis of deduced electrostatic surface potential of the extracellular domain of TLR-7 and -8 resulted in grouping of different species within ruminants.