The [4Fe−4S]2+ Cluster in Reconstituted Biotin Synthase Binds S-Adenosyl-l-methionine

Abstract
The combination of resonance Raman, electron paramagnetic resonance and Mössbauer spectroscopies has been used to investigate the effect of S-adenosyl-l-methionine (SAM) on the spectroscopic properties of the [4Fe−4S]2+ cluster in biotin synthase. The results indicate that SAM interacts directly at a unique iron site of the [4Fe−4S]2+ cluster in BioB and support the hypothesis of a common inner-sphere mechanism for the reductive cleavage of SAM in the radical SAM family of Fe−S enzymes.