Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/27/2017
Publication Date: N/A
Technical Abstract: Chitinase modifying proteins are fungal proteases that attack specific plant defense chitinases. At least three unrelated types of proteases have evolved to have this function. They all truncate the targeted chitinases by cleaving near their amino termini, but each protease type targets a different peptide bond and presumably has its own method of substrate recognition. Polyglycine hydrolases are one of these types. These proteases are fascinating because they have both a novel amino acid sequence and a unique activity. Polyglycine hydrolases were first discovered when their chitinase modifying activity was observed in rotted ears of commercial field corn. Protein purification and peptide sequencing led to the identification of their plant protein substrates and, aided by advances in fungal genomics, of the proteases themselves. Protease assays, both gel and mass spectrometry-based, have revealed how these proteases function. More recently, through the use of site-directed mutagenesis and substrate analog peptides, we are beginning to understand how their unique amino acid sequence relates to protease function.