Structural and functional aspects of PR‐10 proteins

Abstract

Physical, chemical and biological stress factors, such as microbial infection, upregulate the transcription levels of a number of plant genes, coding for the so‐called pathogenesis‐related (PR) proteins. For PR proteins of class‐10 (PR‐10), the biological function remains unclear, despite two decades of scientific research. PR‐10 proteins have a wide distribution throughout the plant kingdom and the class members share size and secondary structure organization. Throughout the years, we and other groups have determined the structures of a number of PR‐10 proteins, both in the crystalline state by X‐ray diffraction and in solution by NMR spectroscopy. Despite the accumulating structural information, our understanding of PR‐10 function is still limited. PR‐10 proteins are rather small (~ 160 amino acids) with a fold consisting of three α helices and seven antiparallel β strands. These structural elements enclose a large hydrophobic cavity that is most probably the key to their functional relevance. Also, the outer surface of these proteins is of extreme interest, as epitopes from a PR‐10 subclass cause allergic reactions in humans.

Structure and Function of the Peanut Panallergen Ara h 8

“…The metal was identified as sodium, which is consistent with previous structural studies of PR-10 proteins (39). For example, an observed Na ϩ binding site overlaps very well with one of the sodium binding sites found in L1PR-10.2B (PDB code 3E85) originating from yellow lupine (40).…”

“…The Bet v 1-like proteins represent a class of proteins called PR-10 (for pathogenesis-related class 10, whose expression increases in response to pathogen attack (39). The function of the Bet v 1 family of proteins has been investigated.…”

“…Some PR-10 proteins have been shown to be up-regulated in response to microbial invasion and have antimicrobial activity (reviewed in Ref. 39). Ara h 8 showed no growth inhibition activity against various Gram-negative and positive bacteria, S. cerevisiae and A. flavus (data not shown).…”

“…Bet v 1 and its homologs from various species have been shown to bind small hydrophobic compounds (reviewed in Ref. 39). Mogensen et al (16) showed that flavonoids, cytokinins, and fatty acids bind to Bet v 1.…”

An Ethylene-Induced Regulatory Module Delays Flower Senescence by Regulating Cytokinin Content

“…PR proteins, which function in a wide range of processes related to signal transduction and antimicrobial activity (Zubini et al, 2009), have been classified into 17 families based on structural features; of these, the PR-10 protein family is a large group containing more than 100 members (Somssich et al, 1988;Biesiadka et al, 2002;Hashimoto et al, 2004;Xu et al, 2014), which are typically small and localized in the cytosol (Fernandes et al, 2013). PR-10 proteins play multifunctional roles in defense mechanisms against abiotic and biotic stresses, and in developmental regulation via their RNase activity and/ or interaction with ligands (Fernandes et al, 2013;Agarwal and Agarwal, 2014). In addition, CTKs can play a role in biological processes that are mediated by PR-10 proteins (Pasternak et al, 2006;Srivastava et al, 2006Srivastava et al, , 2007Fernandes et al, 2008;Zubini et al, 2009).…”