{"id":8661,"date":"2018-02-13T20:16:13","date_gmt":"2018-02-13T20:16:13","guid":{"rendered":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=8661"},"modified":"2018-02-13T20:17:06","modified_gmt":"2018-02-13T20:17:06","slug":"article-journal-of-biological-chemistry-3","status":"publish","type":"post","link":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=8661","title":{"rendered":"Article: Journal of Biological Chemistry"},"content":{"rendered":"<p><a class=\"gsc_a_at\" href=\"http:\/\/www.jbc.org\/content\/early\/2018\/02\/07\/jbc.RA117.001592.abstract\" data-href=\"\/citations?view_op=view_citation&amp;hl=fr&amp;user=u0KB0xMAAAAJ&amp;sortby=pubdate&amp;citation_for_view=u0KB0xMAAAAJ:i2xiXl-TujoC\">Function and maturation of the Fe\u2013S center in dihydroxyacid dehydratase from Arabidopsis\u00a0<\/a>H Gao, T Azam, S Randeniya, J Couturier, N Rouhier, MK Johnson. Journal of Biological Chemistry, jbc. RA117. 001592<\/p>\n<h2>Abstract<\/h2>\n<p id=\"p-2\" style=\"text-align: justify;\">Dihydroxyacid dehydratase (DHAD) is the third enzyme required for branched-chain amino acid biosynthesis in bacteria, fungi, and plants. DHAD enzymes contain two distinct types of active-site Fe\u2013S clusters. The best characterized examples are <em>Escherichia coli<\/em> DHAD, which contains an oxygen-labile [Fe<sub>4<\/sub>S<sub>4<\/sub>] cluster, and spinach DHAD, which contains an oxygen-resistant [Fe<sub>2<\/sub>S<sub>2<\/sub>] cluster. Although the Fe\u2013S cluster is crucial for DHAD function, little is known about the cluster-coordination environment or the mechanism of catalysis and cluster biogenesis. Here, using the combination of UV-visible absorption and circular dichroism, resonance Raman and electron paramagnetic resonance, we spectroscopically characterized the Fe\u2013S center in DHAD from <em>Arabidopsis thaliana<\/em> (<em>At<\/em>). Our results indicated that <em>At<\/em>DHAD can accommodate [Fe<sub>2<\/sub>S<sub>2<\/sub>] and [Fe<sub>4<\/sub>S<sub>4<\/sub>] clusters. However, only the [Fe<sub>2<\/sub>S<sub>2<\/sub>] cluster\u2013bound form is catalytically active. We found that the [Fe<sub>2<\/sub>S<sub>2<\/sub>] cluster is coordinated by at least one non-cysteinyl ligand, which can be replaced by the thiol group(s) of dithiothreitol.<em>In vitro<\/em> cluster transfer and reconstitution reactions revealed that [Fe<sub>2<\/sub>S<sub>2<\/sub>] cluster\u2013containing NFU2 protein is likely the physiological cluster donor for in vivo maturation of <em>At<\/em>DHAD. In summary, <em>At<\/em>DHAD binds either one [Fe<sub>4<\/sub>S4] or one [Fe<sub>2<\/sub>S<sub>2<\/sub>] cluster, with only the latter being catalytically competent and capable of substrate and product binding, and NFU2 appears to be the physiological [Fe<sub>2<\/sub>S<sub>2<\/sub>] cluster donor for DHAD maturation. This work represents the first in vitro characterization of recombinant AtDHAD, providing new insights into the properties, biogenesis, and catalytic role of the active-site Fe\u2013S center in a plant DHAD.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Function and maturation of the Fe\u2013S center in dihydroxyacid dehydratase from Arabidopsis\u00a0H Gao, T Azam, S Randeniya, J Couturier, N Rouhier, MK Johnson. Journal of Biological Chemistry, jbc. RA117. 001592 Abstract Dihydroxyacid dehydratase (DHAD) is the third enzyme required for &hellip; <a href=\"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=8661\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-8661","post","type-post","status-publish","format-standard","hentry","category-academic-productions"],"_links":{"self":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/8661","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8661"}],"version-history":[{"count":0,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/8661\/revisions"}],"wp:attachment":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8661"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8661"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8661"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}