Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Seit Februar 2021 bietet Wolfgang Brandt, ehemaliger Leiter der Arbeitsgruppe Computerchemie am IPB, sein Citizen Science-Projekt zur Pilzbestimmung an. Dafür hat er in regelmäßigen Abständen öffentliche Vorträge zur Vielfalt…
In recent years, the engineering of flexible loops to improve enzyme properties has gained attention in biocatalysis. Herein, we report a loop engineering strategy to improve the stability of the substrate access tunnels, which reveals the molecular mechanism between loops and tunnels. Based on the dynamic tunnel analysis of CYP116B3, five positions (A86, T91, M108, A109, T111) in loops B-B′ and B′-C potentially affecting tunnel frequent occurrence were selected and subjected to simultaneous saturation mutagenesis. The best variant 8G8 (A86T/T91L/M108N/A109M/T111A) for the dealkylation of 7-ethoxycoumarin and the hydroxylation of naphthalene was identified with considerably increased activity (134-fold and 9-fold) through screening. Molecular dynamics simulations showed that the reduced flexibility of loops B-B′ and B′-C was responsible for increasing the stability of the studied tunnel. The redesign of loops B-B′ and B′-C surrounding the tunnel entrance provides loop engineering with a powerful and likely general method to kick on/off the substrate/product transportation.
Publikation
Lee, J.; Romeis, T.;An epiphany for plant resistance proteins and its impact on calcium‐based immune signallingNew Phytol.234769-772(2022)DOI: 10.1111/nph.18085
Zönnchen, J.; Gantner, J.; Lapin, D.; Barthel, K.; Eschen‐Lippold, L.; Lee Erickson, J.; Landeo Villanueva, S.; Zantop, S.; Kretschmer, C.; Joosten, M. H. A. J.; Parker, J. E.; Guerois, R.; Stuttmann, J.;EDS1
complexes are not required for
PRR
responses and execute
TNL‐ETI
from the nucleus in
Nicotiana benthamianaNew Phytol.2362249-2264(2022)DOI: 10.1111/nph.18511
Heterodimeric complexes incorporating the lipase-li ke proteins EDS1 wi th PAD4 or SAG101 are central hubs in plant innate immunity. EDS1 functions encompass signal relay from TIR domain-containing intracellular NLR-type immune receptors (TNLs) towards RPW8-type helper NLRs (RNLs) and, in A. thaliana, bolstering of signaling and resistance mediated by cell-s u r face pattern recognition receptors (PRRs). Increasing evidence points to the activation of EDS1 complexes by small molecule binding. •We used CRISPR/Cas-generated mutant lines and agroinfiltration-based complementation assays to interrogate functions of EDS1 complexes in N. benthamiana. •We do not detect impaired PRR signaling in N. benthamiana lines deficient in EDS1 complexes or RNLs. Intriguingly, in assays monitoring functions of SlEDS1-NbEDS1 complexes in N. benthamiana, mutations within the SlEDS1 catalytic triad can abolish or enhance TNL immunity. Furthermore, nuclear EDS1 accumulation is sufficient for N. benthamianaTNL (Roq1) immunity.•Reinforcing PRR signaling in Arabidopsis might be a derived function of the TNL/EDS1 immune sector. Although Solanaceae EDS1 functionally depends on catalytic triad residues in some contexts, our data do not support binding of a TNL-derived small molecule in the triad environment. Whether and how nuclear EDS1 activity connects to membrane pore-f orming RNLs remains unknown.
Arabidopsis seeds release large capsules of mucilaginous polysaccharides, which are shaped by an intricate network of cellulosic microfibrils. Cellulose synthase complexes are guided by the microtubule cytoskeleton, but it is unclear which proteins mediate this process in the seed coat epidermis. Using reverse genetics, we identified IQ67 DOMAIN 9 (IQD9) and KINESIN LIGHT CHAIN-RELATED 1 (KLCR1) as two highly expressed genes during seed development and comprehensively characterized their roles in cell wall polysaccharide biosynthesis. Mutations in IQD9 as well as in KLCR1 lead to compact mucilage capsules with aberrant cellulose distribution, which can be rescued by transgene complementation. IQD9 physically interacts with KLCR1 and localizes to cortical MTs to maintain their organization in SCE cells. IQD9 as well as a previously identified TONNEAU1 (TON1) RECRUITING MOTIF 4 (TRM4) protein act to maintain cellulose synthase velocity. Our results demonstrate that IQD9, KLCR1 and TRM4 are MT-associated proteins that are required for seed mucilage architecture. This study provides the first direct evidence that members of the IQD, KLCR and TRM families have overlapping roles in cell wall biosynthesis. Therefore, SCE cells provide an attractive system to further decipher the complex genetic regulation of polarized cellulose deposition.