Zymocin, alpha subunit. Zymocin is a heterotrimeric enzyme that inhibits yeast cell cycle progression. The zymocin alpha subunit has a chitinase activity that is essential for holoenzyme action from the cell exterior while the gamma subunit contains the intracellular toxin responsible for G1 phase cell cycle arrest. The zymocin alpha and beta subunits are thought to act from the cell's exterior by docking to the cell wall-associated chitin, thus mediating gamma-toxin translocation. The alpha subunit has an eight-stranded TIM barrel fold similar to that of family 18 glycosyl hydrolases such as hevamine, chitolectin, and chitobiase.
Pathogen effector; putative necrosis-inducing factor. The domain corresponds to the mature part of the Ecp2 effector protein from the tomato pathogen Cladopsorium fulvum. Effectors are low molecular weight proteins that are secreted by bacteria, oomycetes and fungi to manipulate their hosts and adapt to their environment. Ecp2 is a 165 amino acid secreted protein that was originally identified as a virulence factor in C. fulvum, since disruption reduces virulence of the fungus on tomato plants. We have recently determined that Ecp2 is a member of a novel, widely distributed and highly diversified within the fungal kingdom multigene superfamily, which we have designated Hce2, for Homologs of C. fulvum Ecp2 effector. Although Ecp2 is present in most organisms as a small secreted protein, the mature part of this protein can be found fused to other protein domains, including the fungal Glycoside Hydrolase family 18, Glyco_hydro_18 pfam00704 and other, unknown, protein domains. The intrinsic function of Ecp2 remains unknown but it is postulated by that it is a necrosis-inducing factor in plants that serves pathogenicity on the host.
The GH18 (glycosyl hydrolase, family 18) type II chitinases hydrolyze chitin, an abundant polymer of beta-1,4-linked N-acetylglucosamine (GlcNAc) which is a major component of the cell wall of fungi and the exoskeleton of arthropods. Chitinases have been identified in viruses, bacteria, fungi, protozoan parasites, insects, and plants. The structure of the GH18 domain is an eight-stranded beta/alpha barrel with a pronounced active-site cleft at the C-terminal end of the beta-barrel. The GH18 family includes chitotriosidase, chitobiase, hevamine, zymocin-alpha, narbonin, SI-CLP (stabilin-1 interacting chitinase-like protein), IDGF (imaginal disc growth factor), CFLE (cortical fragment-lytic enzyme) spore hydrolase, the type III and type V plant chitinases, the endo-beta-N-acetylglucosaminidases, and the chitolectins. The GH85 (glycosyl hydrolase, family 85) ENGases (endo-beta-N-acetylglucosaminidases) are closely related to the GH18 chitinases and are included in this alignment model.
Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 1 [Ostrinia furnacalis],5Y2B_A Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 1 in complex with HEPTA-N-ACETYLCHITOOCTAOSE (NAG)7 [Ostrinia furnacalis]
7.62e-06
432
702
31
355
Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 1 in complex with a piperidine-thienopyridine derivative [Ostrinia furnacalis],6JAW_A Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 1 in complex with a napthalimide derivative [Ostrinia furnacalis],6JAX_A Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 1 in complex with chitooctaose [(GlcN)8] [Ostrinia furnacalis],6JAY_A Crystal structure of Ostrinia furnacalis Group II chitinase catalytic domain 1 in complex with a dipyrido-pyrimidine derivative [Ostrinia furnacalis]