Analysis of Characteristics, Mutant Sites and Evolution of Dehydrin 6 (DHN6) Protein in Three Types of Rowed Barleys

Abstract

Dehydrins (DHNs), a special polypeptide generated in late embryogenesis of higher plants, could protect the plants from the damage caused by cell dehydration. In order to learn the relationship between characteristics and functions of dehydrins, we cloned Dhn 6 genes from three types of rowed barleys, and bioinformatics analysis showed that they encoded proteins composed of 523 (six-rowed barley), 502 (four-rowed barley) and 486 (two-rowed barley) amino acid residues, respectively. Furthermore, analysis of amino acid mutations found that there were whole conservative traits and mutant sites specificity in this gene. Analyses of protein characteristics and the secondary structure indicated that DHN6 was a highly hydrophilic alkaline protein, and linear structure and numerous random curls were the main component of secondary structure. Moreover, K-segment was involved in the formation of the α-helix, which presumed that the amphipathic α-helices domain of DHN6 might play important roles in protecting membrane structure during the hydration process. The construction of phylogenetic tree of 21 species in this study showed that Dhn 6 gene could be an efficient foundation for identifying and distinguishing of different species associated with special sequences of nucleotides, and had a closer genetic distance in Gramineae crops.