Eight harboured the insertion inside the predicted β-propeller Nutlin-3a nmr domain and six of these eight insertions impaired DspA/E stability or function. Conversely, the two remaining insertions generated proteins that were functional and abundantly secreted in the supernatant suggesting that these two insertions stabilized the protein. “
“The polymorphic

mutation frequencies for 154 Staphylococcus aureus isolates from Chinese bovine clinical mastitis cases were investigated. We found that nearly 29% of the isolates presented as weak mutators, while only two (1.3%) strong mutators were detected. Of the 15 weak mutators that exhibited ciprofloxacin resistance phenotypes, only one isolate was found to be mutS deficient. All of the ciprofloxacin-resistant isolates had the classic ciprofloxacin resistance mutations at codon 80 within the ParC subunit www.selleckchem.com/products/Etopophos.html of topoisomerase IV and codon 84/88 within the GyrA subunit of DNA gyrase. The proportion of ciprofloxacin-resistant

isolates among the weak mutators (34.1%) was significantly higher than that found in the normomutators (11.4%) and hypomutators (0%) (P < 0.001, Fisher's exact test), suggesting a positive correlation between weak mutators and ciprofloxacin resistance. "
“The mercury (II) ion is toxic and is usually detoxified in Bacteria by reduction to elemental mercury, which is less toxic. This is catalysed by an NAD(P)H-dependent mercuric reductase (EC 1.16.1.1). Here, we present strong evidence that Methylococcus capsulatus (Bath) – a methanotrophic member of the Gammaproteobacteria – uses this enzyme to detoxify mercury. In radiorespirometry studies, it was found that cells exposed to mercury dissimilated 100% of [14C]-methane provided to generate reducing

equivalents to fuel Plasmin mercury (II) reduction, rather than the mix of assimilation and dissimilation found in control incubations. The detoxification system is constitutively expressed with a specific activity of 352 (±18) nmol NADH oxidized min−1 (mg protein)−1. Putative mercuric reductase genes were predicted in the M. capsulatus (Bath) genome and found in mRNA microarray studies. The MerA-derived polypeptide showed high identity (> 80%) with MerA sequences from the Betaproteobacteria. Methylococcus capsulatus is a methanotrophic member of the Gammaproteobacteria first isolated from sewage sludge (Foster & Davis, 1966). Whilst the type strain (TexasT) is poorly characterized, the ‘Bath’ strain (Whittenbury et al., 1970) is the archetypal model methanotrophic bacterium. The genome sequence has been completed (Ward et al., 2004; Murrell, 2010) and is available in the GenBank™ database (AE017282). Mercuric ion toxicity to Bacteria occurs because of binding to thiol moieties within proteins. Methanotrophic Bacteria are generally sensitive to mercury (II) (Bowman et al., 1990), although M. capsulatus has not been tested for sensitivity.