Although these features were all seen in Δsahh
strain, a seemingly contradictory observation is that sahh transcript level is elevated in the hypovirus-infected strain. In a plant system, it has been reported that methylation pathway is targeted by geminivirus to Rucaparib purchase inhibit host antiviral defense of transcriptional gene silencing (Buchmann et al., 2009). Very recently SAHH was shown to be targeted by a geminivirus batasatellite-encoded protein to inhibit the SAHH activity and methylation-mediated transcriptional gene silencing (Yang et al., 2011). Should a hypovirus also regulate sahh at posttranslational level to inhibit its enzymatic function, one can hypothesize that elevated
sahh transcription and inhibition of SAHH activity can be two separate events incited by hypovirus infection. In this regard, actually measuring the in vivo SAHH activity by quantification of the SAH/SAM in hypovirus-infected strain will be vitally necessary. As SAHH regulation of the expression this website of genes involved in key process of the cell is likely through its effects on intracellular methylation, further analysis of the genome methylation and global gene expression in Δsahh strain and testing the direct interaction of SAHH and hypovirus-encoded protein(s) will help to reveal the precise mechanisms by which SAHH regulates traits of chestnut blight fungus. This work was supported in part by the National Natural Science Foundation of China grants 31170137, 30130020, and 39925003 and the International Collaboration Key Project 2001CB711104. S.L. and R.L. contributed equally to this work. Please note: Wiley-Blackwell is not responsible for the content 17-DMAG (Alvespimycin) HCl or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. “
“The xnp1 remnant P2-type prophage of Xenorhabdus nematophila produces
xenorhabdicin that is active against closely related species. Xenorhabdicin had not been characterized previously in other Xenorhabdus species. Here, we show xenorhabdicin production in six different strains of Xenorhabdus bovienii. The sequenced genome of X. bovienii SS-2004 was found to possess a highly conserved remnant P2-type cluster (xbp1). Inactivation of the xbpS1 sheath gene resulted in loss of bacteriocin activity, indicating that the xbp1 locus was required for xenorhabdicin production. xbp1 and xnp1 contain a CI-type repressor, a dinI gene involved in stabilization of ssDNA-RecA complexes and are inducible with mitomycin C, suggesting that both loci are regulated by cleavage of the CI repressor.