The proteome-scale study of iron-binding proteins of bread wheat

Iron is an essential micronutrient and plays a vital role in human nutrition and plant development. In this report, we investigated iron-binding proteins (IBPs) of bread wheat at the sequence and structure levels, utilizing high-throughput systematic computational biology and bioinformatic approaches. We found that out of 133 346 wheat proteins, at least 0.97% could bind with iron ions. The analysis revealed numerous significant differences among these IBPs, which are involved in various biological functions. Most of these proteins are localized in plastids, followed by the endoplasmic reticulum, cell membrane and nucleus. But the most diverse group of IBPs are localized in the nucleus and cytoplasm region, being functionally associated with various biological processes. Out of 321 IBP unique domains, most proteins fall under GT1-Gtf-like, protein kinase domain, secretory peroxidases and CYP1. Further categorization and classification of these shortlisted IBPs revealed that most of these proteins are involved in metabolic processes, with oxidoreductase activity being the most prominent gene ontology molecular function (GO: MF), whereas biological process (GO: BP) enrichment highlighted the involvement of these IBPs in the management of reactive oxygen species. Protein interaction and identification of hub genes revealed further important IBP genes that have the potential to be used as a reference sheet for wet-lab work in the development of molecular markers for biofortification and understanding iron homeostasis in wheat.