These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
submitted on 07.06.2019 and posted on 10.06.2019by Hao Yang, Elizabeth C. McDaniel, Stella Impano, Amanda S. Byer, Richard Jodts, Kenichi Yokoyama, William E. Broderick, Joan Broderick, Brian M. Hoffman
The 5'-deoxyadenosyl radical (5'-dAdo•) abstracts a substrate H-atom as the first step in radical-based transformations catalyzed by adenosylcobalamin-dependent and radical S-adenosyl-l-methionine (RS) enzymes. Notwithstanding its central biological role, 5'-dAdo• has eluded characterization despite efforts spanning more than a half-century. Here we report generation of 5'-dAdo• in a RS enzyme active site at 12 K, using a novel approach involving cryogenic photoinduced electron transfer from the [4Fe-4S]+cluster to the coordinated S-adenosylmethionine (SAM) to induce homolytic S-C' bond cleavage.