1b) with MicrobesOnline Operon Predictions (http://www.microbesonline.org/operons/). Five operons, mlr6787-mlr6788, mlr6792-mlr6793, mlr6796-mlr6798-mlr6799, mlr6801-mlr6802-mlr6803-mlr6804, and mlr6806-mlr6807, are polycistronic. Other operons are monocistronic.
Two operons, beginning with mlr6796 and mlr6801, encode proteins that are related to ABC transporters. The functions of three monocistronic genes, mlr6789, mlr6790 and mll6800, are unknown. Besides the mlr6787 operon, five transcriptional units are related to the vitamin B6 degradation pathway I. Additional potential operator sites associated with these genes were searched for. Although several palindrome sequences were found upstream of genes, none of them was similar to the Selleckchem Dasatinib previously identified palindrome sequence (GATTGTCAGACAATC) and we could not find any predicted PyrR binding sites. As a next step, gel retardation assays against the potential regulatory regions should be performed. selleck chemical The effect of the PyrR concentration on the gel-shift of the 135-bp fragment was examined (Fig. 4). The gel-shift was concentration-dependent. With a high concentration
of PyrR (Fig. 4, lanes 8–10), the fragment moved upward as an additional band, suggesting that tetrameric assembly of the PyrR protein had occurred. There are examples of such assembly following DNA binding by Gnt superfamily proteins (Hoskisson & Rigali, 2009). Although the dissociation constant of PyrR was estimated to be 167.9 ± 57.5 μM, based on the density of the main band in lanes 4–7, the value was high and may be an artifact of the blotting technique. Thus, accurate determination of the dissociation constant by another method is required. Pyridoxine induced activities of degrading enzymes (Table 2), indicating that it could work
as an effector molecule. Therefore, pyridoxine and related compounds, Methane monooxygenase pyridoxamine and pyridoxal, were added to the gel retardation assays. When pyridoxal and pyridoxamine were added, the relative amount of the free form of the nucleotide probe increased (Fig. 5), demonstrating that these compounds had an inhibitory effect on binding of PyrR to the DNA. On the other hand, pyridoxine did not appear to prevent DNA binding. Further study will reveal the mode of interaction between PyrR and its effector molecules. “
“Penicillium digitatum, causing citrus green mold, is one of the most devastating pathogenic fungi for postharvest fruits. The disease control is becoming less efficient because of the dispersal of fungicide-resistant strains. However, genome-scale analyses of its resistance mechanism are scarce. In this work, we sequenced the whole genome of the R1 genotype strain Pd01-ZJU and investigated the genes and DNA elements highly associated with drug resistance. Variation in DNA elements related to drug resistance between P.