{"id":15843,"date":"2022-06-27T11:01:10","date_gmt":"2022-06-27T04:01:10","guid":{"rendered":"https:\/\/bgrssb.icgbio.ru\/2022\/?p=15843"},"modified":"2022-09-20T10:32:31","modified_gmt":"2022-09-20T03:32:31","slug":"interaction-of-d-cycloserine-with-a-d-amino-acid-transaminase-from-haliscomenobacter-hydrossis","status":"publish","type":"post","link":"https:\/\/bgrssb.icgbio.ru\/2022\/2022\/06\/27\/interaction-of-d-cycloserine-with-a-d-amino-acid-transaminase-from-haliscomenobacter-hydrossis\/","title":{"rendered":"Interaction of D-cycloserine with a D-amino acid transaminase from Haliscomenobacter hydrossis"},"content":{"rendered":"<p><em>by Alina K. Bakunova | Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian<\/em><br \/>\n<em>Academy of Sciences, Moscow, Russia<\/em><\/p>\n<p><strong>Motivation and Aim:<\/strong><br \/>\nStudying the structures of enzyme complexes with inhibitors is a great way to explore the<br \/>\nsubstrate recognition mode of the enzyme. Recently, we characterized pyridoxal-5\u2019-<br \/>\nphosphate (PLP)-dependent D-amino acid transaminase (DAAT) from bacterium<br \/>\nHaliscomenobacter hydrossis (Halhy) with a new type of the recognition site for the<br \/>\nsubstrate \u03b1-carboxyl group. D-cycloserine (D-CS) is a cyclic analog of serine. Various PLPdependent enzymes, including transaminases (TA), are able to accommodate D-CS in their<br \/>\nactive sites. D-CS is proposed to react with TA through the canonical sequence of reaction<br \/>\nsteps and finally forms irreversibly a stable aromatic compound with PLP or dissociates<br \/>\nfrom the active site. Determination of the structure of the Halhy complex with D-CS can<br \/>\nshed light on both the mechanism of D-CS interaction with Halhy and the mode of substrate<br \/>\nbinding in the active site of the new type of DAAT.<br \/>\n<strong>Methods and Algorithms<\/strong>:<br \/>\nWe explored the interaction of D-CS with Halhy by the combination of UV-Vis spectroscopy,<br \/>\nenzyme kinetics and X-ray crystallography.<br \/>\n<strong>Results<\/strong>:<br \/>\nD-CS is a strong inhibitor of Halhy with IC50 value of 3 \u03bcM. The inhibited enzyme shows an<br \/>\nabsorbance maximum near 330-340 nm, indicative of a completed catalytic half-reaction. In<br \/>\nthe crystal structure D-CS is covalently attached to the cofactor forming a ketimine<br \/>\nintermediate an intermediate product. The ketimine occupies two position. Contrary to<br \/>\nexpectations, D-CS is not held by numerous noncovalent interactions in the active site. The<br \/>\nanalog of a-COOH group is coordinated via Lys241 and the catalytic Lys143.<br \/>\n<strong>Conclusion<\/strong>:<br \/>\nD-CS binds PLP irreversibly; however, the excess of PLP restores the activity of Halhy. via<br \/>\nsubstitution of PLP-D-CS adduct in the active site. In the active site of Halhy D-CS interacts<br \/>\nspecifically with PLP, however, no specific interaction with the residues of the recognition<br \/>\nsite is observed.<\/p>\n<a href=\"https:\/\/bgrssb.icgbio.ru\/2022\/wp-content\/uploads\/sites\/3\/2022\/06\/Bakunova.pdf\" class=\"pdfemb-viewer\" style=\"\" data-width=\"max\" data-height=\"max\"  data-toolbar=\"bottom\" data-toolbar-fixed=\"off\">Bakunova<br\/><\/a>\n","protected":false},"excerpt":{"rendered":"<p>by Alina K. Bakunova | Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences, Moscow, Russia Motivation and Aim: Studying the structures of enzyme complexes with inhibitors is a great way to explore the substrate recognition mode of the enzyme. Recently, we characterized pyridoxal-5\u2019- phosphate (PLP)-dependent D-amino acid transaminase (DAAT) [&hellip;]<\/p>\n","protected":false},"author":3967,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[7],"tags":[229,230,231,232],"_links":{"self":[{"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/posts\/15843"}],"collection":[{"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/users\/3967"}],"replies":[{"embeddable":true,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/comments?post=15843"}],"version-history":[{"count":1,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/posts\/15843\/revisions"}],"predecessor-version":[{"id":15845,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/posts\/15843\/revisions\/15845"}],"wp:attachment":[{"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/media?parent=15843"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/categories?post=15843"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/tags?post=15843"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}