Berndt L

References (5)

Title : Marine Bacteroidetes enzymatically digest xylans from terrestrial plants - Dutschei_2023_Environ.Microbiol__
Author(s) : Dutschei T , Beidler I , Bartosik D , Seesselberg JM , Teune M , Baumgen M , Ferreira SQ , Heldmann J , Nagel F , Krull J , Berndt L , Methling K , Hein M , Becher D , Langer P , Delcea M , Lalk M , Lammers M , Hohne M , Hehemann JH , Schweder T , Bornscheuer UT
Ref : Environ Microbiol , : , 2023
Abstract : Marine Bacteroidetes that degrade polysaccharides contribute to carbon cycling in the ocean. Organic matter, including glycans from terrestrial plants, might enter the oceans through rivers. Whether marine bacteria degrade structurally related glycans from diverse sources including terrestrial plants and marine algae was previously unknown. We show that the marine bacterium Flavimarina sp. Hel_I_48 encodes two polysaccharide utilization loci (PULs) which degrade xylans from terrestrial plants and marine algae. Biochemical experiments revealed activity and specificity of the encoded xylanases and associated enzymes of these PULs. Proteomics indicated that these genomic regions respond to glucuronoxylans and arabinoxylans. Substrate specificities of key enzymes suggest dedicated metabolic pathways for xylan utilization. Some of the xylanases were active on different xylans with the conserved beta-1,4-linked xylose main chain. Enzyme activity was consistent with growth curves showing Flavimarina sp. Hel_I_48 uses structurally different xylans. The observed abundance of related xylan-degrading enzyme repertoires in genomes of other marine Bacteroidetes indicates similar activities are common in the ocean. The here presented data show that certain marine bacteria are genetically and biochemically variable enough to access parts of structurally diverse xylans from terrestrial plants as well as from marine algal sources.
ESTHER : Dutschei_2023_Environ.Microbiol__
PubMedSearch : Dutschei_2023_Environ.Microbiol__
PubMedID: 37121608

Title : Promiscuous Dehalogenase Activity of the Epoxide Hydrolase CorEH from Corynebacterium sp. C12 - Schuiten_2021_ACS.Catal_11_6113
Author(s) : Schuiten ED , Badenhorst CPS , Palm GJ , Berndt L , Lammers M , Mican J , Bednar D , Damborsky J , Bornscheuer UT
Ref : ACS Catal , 11 :6113 , 2021
Abstract : Haloalkane dehalogenases and epoxide hydrolases are phylogenetically related and structurally homologous enzymes that use nucleophilic aspartate residues for an SN2 attack on their substrates. Despite their mechanistic similarities, no enzymes are known that exhibit both epoxide hydrolase and dehalogenase activity. We screened a subset of epoxide hydrolases, closely related to dehalogenases, for dehalogenase activity and found that the epoxide hydrolase CorEH from Corynebacterium sp. C12 exhibits promiscuous dehalogenase activity. Compared to the hydrolysis of epoxides like cyclohexene oxide (1.41 micromol min-1 mg-1), the dehalogenation of haloalkanes like 1-bromobutane (0.25 nmol min-1 mg-1) is about 5000-fold lower. In addition to the activity with 1-bromobutane, dehalogenase activity was detected with other substrates like 1-bromohexane, 1,2-dibromoethane, 1-iodobutane, and 1-iodohexane. This study shows that dual epoxide hydrolase and dehalogenase activity can be present in one naturally occurring protein scaffold.
ESTHER : Schuiten_2021_ACS.Catal_11_6113
PubMedSearch : Schuiten_2021_ACS.Catal_11_6113
Gene_locus related to this paper: corsp-cEH

Title : Discovery and Design of Family VIII Carboxylesterases as Highly Efficient Acyltransferases - Muller_2021_Angew.Chem.Int.Ed.Engl_60_2013
Author(s) : Muller H , Godehard SP , Palm GJ , Berndt L , Badenhorst CPS , Becker AK , Lammers M , Bornscheuer UT
Ref : Angew Chem Int Ed Engl , 60 :2013 , 2021
Abstract : Promiscuous acyltransferase activity is the ability of certain hydrolases to preferentially catalyze acyl transfer over hydrolysis, even in bulk water. However, poor enantioselectivity, low transfer efficiency, significant product hydrolysis, and limited substrate scope represent considerable drawbacks for their application. By activity-based screening of several hydrolases, we identified the family VIII carboxylesterase, EstCE1, as an unprecedentedly efficient acyltransferase. EstCE1 catalyzes the irreversible amidation and carbamoylation of amines in water, which enabled the synthesis of the drug moclobemide from methyl 4-chlorobenzoate and 4-(2-aminoethyl)morpholine (ca. 20% conversion). We solved the crystal structure of EstCE1 and detailed structure-function analysis revealed a three-amino acid motif important for promiscuous acyltransferase activity. Introducing this motif into an esterase without acetyltransferase activity transformed a "hydrolase" into an "acyltransferase".
ESTHER : Muller_2021_Angew.Chem.Int.Ed.Engl_60_2013
PubMedSearch : Muller_2021_Angew.Chem.Int.Ed.Engl_60_2013
PubMedID: 33140887

Title : Sequence-Based Prediction of Promiscuous Acyltransferase Activity in Hydrolases - Muller_2020_Angew.Chem.Int.Ed.Engl_59_11607
Author(s) : Muller H , Becker AK , Palm GJ , Berndt L , Badenhorst CPS , Godehard SP , Reisky L , Lammers M , Bornscheuer U
Ref : Angew Chem Int Ed Engl , 59 :11607 , 2020
Abstract : Certain hydrolases preferentially catalyze acyl transfer over hydrolysis in an aqueous environment. However, molecular and structural reasons for this phenomenon are still unclear. Here we provide evidence that acyltransferase activity in esterases highly correlates with the hydrophobicity of the substrate-binding pocket. A hydrophobicity scoring system developed in this work allows accurate prediction of promiscuous acyltransferase activity solely from the amino acid sequence of the cap domain. This concept was experimentally verified by systematic investigation of several homologous esterases, leading to the discovery of five novel promiscuous acyltransferases. We also developed a simple, yet versatile, colorimetric assay for rapid characterization of novel acyltransferases. This study demonstrates that promiscuous acyltransferase activity is not as rare as previously thought and provides access to a vast number of novel acyltransferases with diverse substrate specificities and potential applications.
ESTHER : Muller_2020_Angew.Chem.Int.Ed.Engl_59_11607
PubMedSearch : Muller_2020_Angew.Chem.Int.Ed.Engl_59_11607
PubMedID: 32243661
Gene_locus related to this paper: 9bact-Est8.6Y9K

Title : Structure of the plastic-degrading Ideonella sakaiensis MHETase bound to a substrate - Palm_2019_Nat.Commun_10_1717
Author(s) : Palm GJ , Reisky L , Bottcher D , Muller H , Michels EAP , Walczak MC , Berndt L , Weiss MS , Bornscheuer UT , Weber G
Ref : Nat Commun , 10 :1717 , 2019
Abstract : The extreme durability of polyethylene terephthalate (PET) debris has rendered it a long-term environmental burden. At the same time, current recycling efforts still lack sustainability. Two recently discovered bacterial enzymes that specifically degrade PET represent a promising solution. First, Ideonella sakaiensis PETase, a structurally well-characterized consensus alpha/beta-hydrolase fold enzyme, converts PET to mono-(2-hydroxyethyl) terephthalate (MHET). MHETase, the second key enzyme, hydrolyzes MHET to the PET educts terephthalate and ethylene glycol. Here, we report the crystal structures of active ligand-free MHETase and MHETase bound to a nonhydrolyzable MHET analog. MHETase, which is reminiscent of feruloyl esterases, possesses a classic alpha/beta-hydrolase domain and a lid domain conferring substrate specificity. In the light of structure-based mapping of the active site, activity assays, mutagenesis studies and a first structure-guided alteration of substrate specificity towards bis-(2-hydroxyethyl) terephthalate (BHET) reported here, we anticipate MHETase to be a valuable resource to further advance enzymatic plastic degradation.
ESTHER : Palm_2019_Nat.Commun_10_1717
PubMedSearch : Palm_2019_Nat.Commun_10_1717
PubMedID: 30979881
Gene_locus related to this paper: idesa-mheth