, 2004). Our results warrant further investigation of how X. fastidiosa would
respond to the AMPs produced by citrus endophytes and by the insect vector. Understanding how these AMPs interfere with bacterial virulence could provide novel tools for disease control. We are grateful to Ricardo Vêncio, Tie Koide and José F. da Silva-Neto for suggestions. We thank Alexandre Sanchez, Adriana Matsukuma and Denise Yamamoto for technical assistance. this website This work was funded by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) grants to A.M.d.S. A.C.F., P.A.Z. and P.I.P.d.S. received fellowships from FAPESP. A.M.d.S. and S.D. were partially supported by CNPq. Table S1. Selected CDS of Xylella fastidiosa differentially expressed by treatment with 50 μM of gomesin. Please note: Wiley-Blackwell is not responsible for
the content 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. “
“Either of two related molybdenum-responsive regulators, MopA and MopB, of Rhodobacter capsulatus is sufficient to repress the nitrogen-fixation gene anfA. In Birinapant contrast, MopA (but not MopB) activates mop, which codes for a molybdate (Mo)-binding molbindin. Both regulators bind to conserved cis-regulatory elements called Mo-boxes. Single-base substitution of two highly conserved nucleotides within the anfA-Mo-box (T21C and C24T) had little effect on regulator binding and anfA expression as shown by
DNA mobility shift assays and reporter gene fusions, respectively. In contrast to C24T, mutation C24A strongly diminished binding and repression by MopA and MopB, showing that different nucleotide substitutions at the same position may have very different effects. A triple mutation destroying the left half-site of the mop-Mo-box completely abolished mop expression Amrubicin by MopA, demonstrating the importance of the mop-Mo-box for mop activation. Two point mutations (T23A and T24C) still allowed binding by MopA, but abolished mop activation, most likely because these nucleotides overlap with the RNA polymerase-binding site. A mutant mop promoter, in which the mop-Mo-box was exchanged against the anfA-Mo-box, allowed activation by MopA, showing that a former repressor-binding site may act as an activator-binding site depending on its location relative to the other promoter elements. Bacteria have evolved multiple metal homeostasis mechanisms controlling high-affinity uptake systems under metal-limiting conditions, synthesis of metal-containing cofactors, and, under metal-excess conditions, detoxification and export (O’Halloran, 1993; Hernandez et al., 2009; Waldron et al., 2009).