Many drug candidate molecules contain at least one chiral centre, and consequently, the development of biocatalytic strategies to complement existing metal‐ and organocatalytic approaches is of high interest. However, time is a critical factor in chemical process development, and thus, the introduction of biocatalytic steps, even if more suitable, is often prevented by the limited availability of off‐the‐shelf enzyme libraries. To expand the biocatalytic toolbox with additional ene reductases, we screened 19 bacterial strains for double bond reduction activity by using the model substrates cyclohexanone and carvone. Overall, we identified 47 genes coding for putative ene reductases. Remarkably, bioinformatic analysis of all genes and the biochemical characterization of four representative novel ene reductases led us to propose the existence of two new Old Yellow Enzyme subclasses, which we named OYE class III and class IV. Our results demonstrate that although, on a DNA level, each new OYE subclass features a distinct combination of sequence motifs previously known from the classical and the thermophilic‐like group, their substrate scope more closely resembles the latter subclass.

Three ionophores were used to investigate a potential role of the plasma-membrane (PM) potential in the regulation of systemic wound-response gene expression in tomato (Lycopersicon escuilentum Mill.) plants. Valinomycin, nigericin, and gramicidin, which affect the PM potential by dissipating H+ and K+ gradients, respectively, induced the rapid accumulation of wound-response gene transcripts. Transcript induction by gramicidin was kinetically, qualitatively and quantitatively similar to systemin-induced transcript accumulation. On a molar basis, gramicidin and nigericin, which affect gradients of both H+ and K+, were more effective than the K+-selective valinomycin. Hyperpolarization of the PM by fusicoccin, on the other hand, repressed wound-response gene expression and, at the same time, induced salicylic acid (SA) accumulation and the expression of pathogenesis-related proteins. We show here that the inhibition of the wound response after fusicoccin treatment is not mediated by elevated concentrations of SA but is likely a direct effect of PM hyperpolarization. The data indicate a role for the PM potential in the differential regulation of wound and pathogen defense responses.

Within the frame of a biotechnological screening, we isolated two Pseudomonas strains from forest soil. 16S rRNA gene sequence analysis indicated that strain CCOS 864T shared 99.8 % similarity with Pseudomonas donghuensis HYST, while strain CCOS 865T shared 99.0 % similarity with Pseudomonas putida DSM 291T and lower similarity with other P. putida group type strains. Based on multilocus sequence analysis, the two strains were genotypically distinct from each other, each forming a separate clade. Strains CCOS 864T and CCOS 865T were Gram-stain-negative, motile and rod-shaped, growing at a temperature range of 4-37 °C. Strain CCOS 864T could be phenotypically distinguished from P. putida group species by the combination of gelatinase-positive reaction and positive growth on N-acetyl-d-glucosamine, p-hydroxyphenylacetic acid and inosine but lack of fluorescein production on King's B medium, while strain CCOS 865T could be distinguished from P. putida group species by the combination of positive growth with saccharic acid and negative growth with p-hydroxyphenylacetic acid and l-pyroglutamic acid. The major polar lipid for both strains was phosphatidylethanolamine; the major quinone was ubiquinone Q-9. DNA-DNA hybridization and average nucleotide identities confirmed the novel species status for the two strains. The DNA G+C contents of CCOS 864T and CCOS 865T were 62.1 and 63.8 mol%, respectively. The phenotypic, phylogenetic and DNA-DNA relatedness data support the suggestion that CCOS 864T and CCOS 865T represent two novel Pseudomonas species. The names Pseudomonas wadenswilerensis sp. nov. (type strain CCOS 864T=LMG 29327T) and Pseudomonas reidholzensis sp. nov. (type strain CCOS 865T=LMG 29328T) are proposed.

Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Sentrin-specific proteases (SENPs) are responsible for the maturation of small ubiquitin-like modifiers (SUMOs) and the deconjugation of SUMOs from their substrate proteins. Studies on prostate cancer revealed an overexpression of SENP1, which promotes prostate cancer progression as well as metastasis. Therefore, SENP1 has been identified as a novel drug target against prostate cancer. Herein, we report the discovery and biological evaluation of potent and selective SENP1 inhibitors. A structure-activity relationship (SAR) of the newly identified pyridone scaffold revealed allosteric inhibitors with very attractive in vitro ADMET properties regarding plasma binding and plasma stability for this challenging target. This study also emphasizes the importance of biochemical mode of inhibition studies for de novo designed inhibitors.