Molecular Evolution of Miraculin-Like Proteins in Soybean Kunitz Super-Family

Abstract

Miraculin-like proteins (MLPs) belong to soybean Kunitz super-family and have been characterized from many plant families like Rutaceae, Solanaceae, Rubiaceae, etc. Many of them possess trypsin inhibitory activity and are involved in plant defense. MLPs exhibit significant sequence identity (~30-95%) to native miraculin protein, also belonging to Kunitz super-family compared with a typical Kunitz family member (~30%). The sequence and structure-function comparison of MLPs with that of a classical Kunitz inhibitor have demonstrated that MLPs have evolved to form a distinct group within Kunitz super-family. Sequence analysis of new genes along with available MLP sequences in the literature revealed three major groups for these proteins. A significant feature of Rutaceae MLP type 2 sequences is the presence of phosphorylation motif. Subtle changes are seen in putative reactive loop residues among different MLPs suggesting altered specificities to specific proteases. In phylogenetic analysis, Rutaceae MLP type 1 and type 2 proteins clustered together on separate branches, whereas native miraculin along with other MLPs formed distinct clusters. Site-specific positive Darwinian selection was observed at many sites in both the groups of Rutaceae MLP sequences with most of the residues undergoing positive selection located in loop regions. The results demonstrate the sequence and thereby the structure-function divergence of MLPs as a distinct group within soybean Kunitz super-family due to biotic and abiotic stresses of local environment.

RNA-seq transcriptome profiling reveals that Medicago truncatula nodules acclimate N 2 fixation before emerging P deficiency reaches the nodules

“…log 2 FC of –3.52, RPKM control 1635). Miraculin itself is a glycoprotein, possesses trypsin inhibitory activity and is involved in the plant’s response to pathogens ( Hiraoka et al , 2009 ; Selvakumar et al , 2012 ). On the human tongue, the protein pH-dependently activates the activity of a sweet taste receptor ( Koizumi et al , 2011 ).…”

Resistance to Streptomyces turgidiscabies in potato involves an early and sustained transcriptional reprogramming at initial stages of tuber formation

“…One isoform of the mlp34 gene (GG18787c3_g1_i2) was found in both infected and uninfected ‘Beate’ plants, but was not detected in ‘Saturna’. Genes encoding miraculin‐like proteins (MLPs) are known to play a role in plant defence (Selvakumar et al ., ; Tsukuda et al ., ). Two other genes that were highly up‐regulated in ‘Beate’, and known to be involved in the regulation of plant defence in response to pathogen attack, were the myb4 (GG32600c6_g1_i4) and myb86 (GG28885c13_g1_i1) genes that belong to the myeloblastosis (MYB) family of transcription factors (Raffaele and Rivas, ; van Verk et al ., ).…”

Phytochemical Analysis of Some Selected Plants and Families in the University Botanic Garden Of Maseno, Kenya.

“…The plant families Solanaceae and Rutaceae all have phytochemical composition mean of 60.0, indicating that the families are closely related. The close relationship between the Solanaceae and Rutaceae plant families is supported by Selvakumare, Gahloth, Tomar, SharmaandSharma,(2011) [34]in their "Molecular evolution of miraculin-like proteins study" which indicates that members of these two plant families contain these proteins. Many of them possess trypsin inhibitory activity, involved in plant defense.…”