crescentus     NA1000 Also CB15N, synchronizable derivative of wild-type CB15 [49] MM46 NA1000 ΔnczA (ΔCCNA_02473) This work MM47 NA1000 ΔczrA (ΔCCNA_02809) This work MM48 NA1000ΔczrAΔnczA This work MM46+ MM46 xylX::nczA This work MM47+ MM47 xylX::czrA This work Plasmids     pGEM-T Easy Cloning vector; Ampr Promega pRKlacZ290 pRK2-derived vector with a promoterless lacZ gene; Tetr [50] pNPTS138 Suicide vector used for gene disruption containing oriT and sacB; Kanr D. Alley pNPT228XNE xylX locus in pNPT228; Kanr [51] Cloning of the

promoter regions and β-galactosidase FDA approved Drug Library activity assays Regulatory regions upstream of C. crescentus NA1000 ORFs CCNA_02805 (between −379 and +75 relative to the ATG), CCNA_02806 (between −374 and +56) and CCNA_02471 (between −675 and +188) were amplified from purified chromosomal DNA by PCR with Platinum Pfx DNA polymerase (Life Technologies) and specific primers (Table 3): RND1/RND2 (Pczc1), RND3/RND4 (Pczc1a) and RND5/RND6 (Pczc2). The amplified fragments were cloned into pGEM-T Easy (Promega) and confirmed by DNA sequencing. Each fragment was ligated upstream of the lacZ gene on pRKlacZ290 and the recombinant plasmids were transferred to C. crescentus strain NA1000. Table 3 Primers used in this study Nome      Sequence (5′- → 3′ )a RND1 GGAATTCGCGATTGGCTAACGG RND2 CAAGCTTGACCAACGCAACCAAG

RND3 GGAATTCGCCATCTGCGCCAACGATT RND4 CAAGCTTCTCATGAAGCCTAGAG RND5 BMS345541 manufacturer GGGATCCGCCGGATCCCTCCGATGTGAAGAGG RND6 click here CCTGCAGCGGACGCCGGCCTCTGCAGCCGC RND7 CAAGCTTCATCCTCACCCTGAGACAA RND8 GGAATTCAGAGATCCAAGATCCTG

RND9 GGAATTCGATCTGCCGGTTCGTCCTG RND10 CGACGCGTTAGCCTCTTTCAATGTGAAGAC RND11 CAAGCTTCTACCAAGGGCGGTCGCAT RND12 GGGATCCTGGTCGCCTCCCTAATGGT RND13 GGGATCCCATTGAGCCTCCGCCAGCT RND14 CGACGCGTCTATAGTACCATCGCAATAC RND15 GACTAGTATGATCGGCAGGATCTTGGAT RND16 GACTAGTTTAGGCTCCTTGCTCTTGA RND17 GGAATTCATGCTTGAACGCATCATCGCC RND18 GACTAGTCTATCGTACCGCCCTGGCTTG a Boldface letters indicate restriction enzyme recognition sites, used for cloning purposes. Growth phase-dependent promoter activity was measured Astemizole by β-galactosidase assays [38], from exponential or stationary phase (24 h) cultures grown in PYE-tetracycline. Expression driven from promoters Pczc1 and Pczc2 was also evaluated in the presence of divalent cations (Sigma) at the following concentrations: 10 μM CdCl2; 100 μM ZnCl2; 100 μM CoCl2; or 100 μM NiCl2. Cultures grown in PYE-tetracycline at 30°C were diluted to an initial optical density at 600 nm (OD600) of 0.1, and the divalent metal was added when they reached OD600 0.5. Aliquots were taken before and at several time points after metal addition and expression was measured by β-galactosidase assays. Statistical treatment of the data was carried out using Student’s T-Test. RT-PCR Total RNA from exponentially growing C.