Ferredoxins as interchangeable redox components in support of MiaB, a radical S-adenosylmethionine methylthiotransferase.

ABSTRACT: MiaB is a member of the methylthiotransferase subclass of the radical S-adenosylmethionine (SAM) superfamily of enzymes, catalyzing the methylthiolation of C2 of adenosines bearing an N⁶ -isopentenyl (i⁶ A) group found at position 37 in several tRNAs to afford 2-methylthio-N⁶ -(isopentenyl)adenosine (ms² i⁶ A). MiaB uses a reduced [4Fe-4S]⁺ cluster to catalyze a reductive cleavage of SAM to generate a 5'-deoxyadenosyl 5'-radical (5'-dA•)-a required intermediate in its reaction-as well as an additional [4Fe-4S]²⁺ auxiliary cluster. In Escherichia coli and many other organisms, re-reduction of the [4Fe-4S]²⁺ cluster to the [4Fe-4S]⁺ state is accomplished by the flavodoxin reducing system. Most

SUBMITTER: Arcinas AJ 

PROVIDER: S-EPMC6295894 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature