The Gram-negative soil bacterium Serratia marcescens uses three different family 18 chitinases to degrade chitin, an abundant insoluble carbohydrate polymer composed of beta(1,4)-linked units of N-acetylglucosamine. We show that efficient chitin degradation additionally depends on the action of a small non-catalytic protein, CBP21, which binds to the insoluble crystalline substrate, leading to ...

Peritrophic membranes (PMs) are composed of proteins, proteoglycans and chitin that play important roles in the structural formation and function of the PM. This study identified and characterized a new chitin binding protein named HpCBP45 by immunoscreening of the Holotrichia parallela larvae midgut expression library. The predicted amino acid sequence indicates that it contains eight tandem ch...

Peptidoglycan recognition proteins (PGRPs), which have been identified in most animals, are pattern recognition molecules that involve antimicrobial defense. Resulting from extraordinary expansion of innate immune genes, the amphioxus encodes many PGRPs of diverse functions. For instance, three isoforms of PGRP encoded by Branchiostoma belcheri tsingtauense, termed BbtPGRP1~3, are fused with a ...

Protein extracts from soybean (Glycine max [L.] Merr) seed hulls were fractionated by isoelectric focusing and SDS-PAGE analysis and components identified by peptide microsequencing. An abundant 32 kDa protein possessed an N-terminal cysteine-rich hevein domain present in class I chitinases and in other chitin-binding proteins. The protein could be purified from seed coats by single step bindin...

Genome sequence of Serratia proteamaculans 568 revealed the presence of three family 33 chitin binding proteins (CBPs). The three Sp CBPs (Sp CBP21, Sp CBP28 and Sp CBP50) were heterologously expressed and purified. Sp CBP21 and Sp CBP50 showed binding preference to β-chitin, while Sp CBP28 did not bind to chitin and cellulose substrates. Both Sp CBP21 and Sp CBP50 were synergistic with four ch...

Chitinase Chi1 of Aeromonas caviae CB101 possesses chitin binding sites at both its N and C termini. Four putative exposed residues aligned in a line on the surface of the N-terminal domains of Chi1 were found to contribute to the enzyme-chitin binding and hydrolysis via site-directed mutagenesis. Also, it was found that Chi1 requires the cooperation of the N- and C-terminal domains to bind ful...

Some oomycetes species are severe pathogens of fish or crops. As such, they are responsible for important losses in the aquaculture industry as well as in agriculture. Saprolegnia parasitica is a major concern in aquaculture as there is currently no method available for controlling the diseases caused by this microorganism. The cell wall is an extracellular matrix composed essentially of polysa...

BACKGROUND The infectious and diagnostic form of Entamoeba histolytica (Eh), cause of amebic dysentery and liver abscess, is the quadranucleate cyst. The cyst wall of Entamoeba invadens (Ei), a model for Eh, is composed of chitin fibrils and three sets of chitin-binding lectins that cross-link chitin fibrils (multivalent Jacob lectins), self-aggregate (Jessie lectins), and remodel chitin (chiti...

Class V chitin synthases are fungal virulence factors required for plant infection. They consist of a myosin motor domain fused to a membrane-spanning chitin synthase region that participates in fungal cell wall formation. The function of the motor domain is unknown, but it might deliver the myosin chitin synthase-attached vesicles to the growth region. Here, we analyze the importance of both d...