Skip to main content
. Author manuscript; available in PMC: 2014 Jul 7.
Published in final edited form as: Curr Opin Struct Biol. 2012 Nov 8;22(6):701–710. doi: 10.1016/j.sbi.2012.10.005

Figure 1.

Figure 1

The reductive cleavage of SAM catalyzed by RS enzymes. SAM is coordinated via its amino and carboxyl moieties to the unique iron of a [4Fe–4S] cluster (left). The reduced [4Fe–4S]+ cluster transfers an electron to SAM, thereby promoting homolytic cleavage to generate methionine and a 5′-deoxyadenosyl radical. The 5′-deoxyadenosyl radical abstracts a hydrogen atom from substrate (SH) to produce a substrate radical (S•), methionine, and 5′-deoxyadenosine (right).