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dc.contributor.authorHillier, Heidi Therese
dc.contributor.authorAltermark, Bjørn
dc.contributor.authorLeiros, Ingar
dc.date.accessioned2021-04-19T09:35:12Z
dc.date.available2021-04-19T09:35:12Z
dc.date.issued2020-02-29
dc.description.abstractL‐2,4‐diaminobutyric acid (DABA) aminotransferases can catalyze the formation of amines at the distal ω‐position of substrates, and is the intial and rate‐limiting enzyme in the biosynthesis pathway of the cytoprotecting molecule (S)‐2‐methyl‐1,4,5,6‐tetrahydro‐4‐pyrimidine carboxylic acid (ectoine). Although there is an industrial interest in the biosynthesis of ectoine, the DABA aminotransferases remain poorly characterized. Herein, we present the crystal structure of EctB (2.45 Å), a DABA aminotransferase from <i>Chromohalobacter salexigens</i> DSM 3043, a well‐studied organism with respect to osmoadaptation by ectoine biosynthesis. We investigate the enzyme’s oligomeric state to show that EctB from <i>C. salexigens</i> is a tetramer of two functional dimers, and suggest conserved recognition sites for dimerization that also includes the characteristic gating loop that helps shape the active site of the neighboring monomer. Although ω‐transaminases are known to have two binding pockets to accommodate for their dual substrate specificity, we herein provide the first description of two binding pockets in the active site that may account for the catalytic character of DABA aminotransferases. Furthermore, our biochemical data reveal that the EctB enzyme from <i>C. salexigens</i> is a thermostable, halotolerant enzyme with a broad pH tolerance which may be linked to its tetrameric state. Put together, this study creates a solid foundation for a deeper structural understanding of DABA aminotransferases and opening up for future downstream studies of EctB’s catalytic character and its redesign as a better catalyst for ectoine biosynthesis. In summary, we believe that the EctB enzyme from <i>C. salexigens</i> can serve as a benchmark enzyme for characterization of DABA aminotransferases.en_US
dc.identifier.citationHillier HT, Altermark B, Leiros I. The crystal structure of the tetrameric DABA-aminotransferase EctB, a rate-limiting enzyme in the ectoine biosynthesis pathway.. The FEBS Journal. 2020en_US
dc.identifier.cristinIDFRIDAID 1803185
dc.identifier.doi10.1111/febs.15265
dc.identifier.issn1742-464X
dc.identifier.issn1742-4658
dc.identifier.urihttps://hdl.handle.net/10037/20934
dc.language.isoengen_US
dc.publisherWileyen_US
dc.relation.journalThe FEBS Journal
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/SYNKNØYT/247732/Norway/Reisestøtte, synkrotron- og nøytronforskning, 2015-2017//en_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2020 The Author(s)en_US
dc.subjectVDP::Mathematics and natural science: 400::Physics: 430en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Fysikk: 430en_US
dc.titleThe crystal structure of the tetrameric DABA-aminotransferase EctB, a rate-limiting enzyme in the ectoine biosynthesis pathwayen_US
dc.type.versionpublishedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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