Not all 5'-deoxyadenosines are created equal: Tracing the provenance of 5'-deoxyadenosine formed by the radical S-adenosyl-L-methionine enzyme 7-carboxy-7-deazaguanine synthase.

ABSTRACT: Members of the radical S-adenosyl-L-methionine (rSAM) enzyme superfamily cleave SAM to generate the highly reactive 5'-deoxyadenosyl radical (dAdo·), where dAdo· initiates the reaction by an H-atom transfer from the substrate to form 5'-deoxyadenosine (dAdo) in nearly every member of the superfamily. However, in all rSAM enzymes, SAM also undergoes reductive cleavage to form dAdo in a reaction uncoupled from the product's formation. Herein, we examine the dAdo that is formed under catalytic conditions with the rSAM enzyme 7-carboxy-7-deazaguanine synthase (QueE), which catalyzes the radical-mediated transformation of 6-carboxy-5,6,7,8-tetrahydropterin (CPH₄) to 7-carboxy-7-deazaguanine (CDG). We propose that the dAdo that is observed under catalytic conditions can be traced to m

SUBMITTER: Nayak S 

PROVIDER: S-EPMC11994313 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature