infestans. However, when the CAZy annotation pipeline http://www.selleckchem.com/products/ABT-263.html was applied to Ph. sojae, Ph. ramorum and Ph. infestans, 301, 258 and 277 GHs were found, respectively, nearly twice the number present in P. ultimum. Among these we iden tified putative cellulases belonging to families GH5, GH6 and GH7. All six GH6 candidate cellulases harbor secretion signals. Only one GH6 protein contains a CBEL domain at the carboxyl terminus. Three contain a transmembrane domain and one contains a glycosylpho sphatidylinisotol anchor, features suggesting that these proteins may be targeting the oomycete cell wall rather than plant cell walls. The P. ultimum Inhibitors,Modulators,Libraries strain studied here could not grow when cellulose was the sole carbon source. Cutinases are a particular set of esterases that cleave cutin, a polyester composed of hydroxy and hydroxyepoxy fatty acids that protects aer ial plant organs.
No candidate cutinases could be found in the P. ultimum genome. Cutinase activity was reported Inhibitors,Modulators,Libraries in culture filtrates Inhibitors,Modulators,Libraries of P. ultimum, but its growth was not supported on apple cutin and low levels of fatty acid esterase were detected in P. ultimum only in 21 day old culture. The absence of recog nizable cutinases suggests these enzymes are not critical for penetration and infection by P. ultimum, which attacks young, non suberized roots and penetrates tis sues indirectly through wounds. This contrasts with the number of putative cutinases identified in several Phy tophthora spp. which presumably promote penetration of leaf and stem tissues that are protected by a thick cuticle or colonization of heavily suberized root and bark tissue.
The Inhibitors,Modulators,Libraries xylan degrading capacity of P. ultimum appears to be limited, if not totally absent. No members of the GH10 and GH11 families encoding endoxylanases essential for xylan degradation could be found. Further more, families involved in the removal of xylan side chains Inhibitors,Modulators,Libraries or modifications such as GH67, CE3, and CE5 are absent while families CE1 and CE2 contain only a limited number of members. The lack of significant xylan digestion was confirmed by the absence of growth when xylan was used as a carbon source, consistent with previous work on P. ultimum and other Pythium spp. Pectinases play a key role in infection by Pythium spp. Twenty nine candidate pectin pectate lyases are present in P. ultimum while the genomes of Phytophthora spp. encode even larger PL families.
In P. ultimum, the set of pectin lyases is complemented by 11 pectin hydrolases from family GH28, several selleck chemicals 17-DMAG of which having been func tionally characterized in various Phytophthora spp. P. ultimum lacks pectin methylesterases as well as genes encoding family GH88 and GH105 enzymes and therefore cannot fully saccharify the products of pectin pectate lyases, consistent with previous reports of incomplete pectin degradation and little or no galacturo nic acid production during P. ultimum infection of bent grass.