The structure of an allosamidin complex with the Coccidioides immitis chitinase defines a role for a second acid residue in substrate-assisted mechanism.

Allosamidin is a known inhibitor of class 18 chitinases. We show that allosamidin is a competitive inhibitor of the fungal chitinase CiX1 from Coccidioides immitis, with a K(i) of 60 nM. We report the X-ray structure of the complex and show that upon inhibitor binding the side-chain of Asp169 rotates to form an ion pair with the oxazolinium cation.

Kinetic properties of chitinase-1 from the fungal pathogen Coccidioides immitis.

The endochitinase from Coccidioides immitis (CiX1) is a member of the class 18 chitinase family. Here we show the enzyme functions by a retaining catalytic mechanism; that is, the beta-conformation of the chitin substrate linkages is preserved after hydrolysis. The pattern of cleavage of N-acetyglucosamine (GlcNAc) oligosaccharide substrates has been determined.

The X-ray structure of a chitinase from the pathogenic fungus Coccidioides immitis.

The X-ray structure of chitinase from the fungal pathogen Coccidioides immitis has been solved to 2.2 A resolution. Like other members of the class 18 hydrolase family, this 427 residue protein is an eight-stranded beta/alpha-barrel.

Partially formed native tertiary interactions in the A-state of cytochrome c.

Considerable insight into protein structure, stability, and folding has been obtained from studies of non-native states. We have studied the extent of native tertiary contacts in one such molecule, the A-state of yeast iso-1-ferricytochrome c. Previously, we showed that the interface between the N and C-terminal helices is completely formed in the A-state.

Crystallization and preliminary X-ray analysis of a chitinase from the fungal pathogen Coccidioides immitis.

Chitinase is necessary for fungal growth and cell division and, therefore, is an ideal target for the design of inhibitors which may act as antifungal agents. A chitinase from the fungal pathogen Coccidioides immitis has been expressed as a fusion protein with gluathione-S-transferase (GST), which aids in purification. After cleavage from GST, chitinase was crystallized from 30% PEG 4000 in 0.