Comparative evolutionary and structural bioinformatic analysis of the human N-Acetyltransferase-2 (NAT2) gene with different mammalian and avian taxa

Effective metabolization of exogenous compounds in humans is a key for health and drug efficacy albeit a complex process determined by one's genetic background. The enzyme, N-Acetyltransferase-2 (NAT2), which metabolizes different xenobiotic compounds (including folate) and various therapeutic drugs, is encoded by the NAT2 gene. Based on acetylation capacity, an individual is either a fast or slow acetylator. Although the apportionment of NAT2 gene and its acetylator types are widely documented in human populations, the evolutionary genetic affinities and functional background of NAT2 variations with closely-related taxa are not well understood. Herein, we have analyzed 60 NAT2 gene coding sequences (873 bp) representing 59 different taxa belonging to mammalian and avian taxa and two most prevalent human NAT2 alleles ((NAT2*4 and NAT2*6A) to document the phylogenetics relationship among taxa; to characterize DNA methylation patterns in this gene and to evaluate species specific binding efficiency to folate using molecular docking approach. Phylogenetic analysis showed 3 broad clades representing where humans and other primates were found to be closely related. The CpG analysis revealed a one conserved region of same length (total 200 bp) across taxa as well as variable short regions of differing lengths (ranging from minimum 50 to maximum 100 bp length sequences) in some taxa. Molecular docking showed variable binding affinities of NAT2 protein models with human slow acetylator allele (NAT2*6A) showing highest binding affinity to folate, indicative of adaptive response to folate bioavailability. Through our analysis we highlight the evolutionary conservation and functional divergence in NAT2 gene across Mammals and Aves likely to be driven by ecological and dietary factors. Our findings provide new insights into evolutionary adaptations to processing folate across various taxa, which may be significant in studies focusing on evolutionary genetics of drug metabolism.