Spore Photoproduct Lyase: the Known, the Controversial, and the Unknown [Enzymology]

December 4th, 2014 by Yang, L., Li, L.

Spore photoproduct lyase (SPL) repairs 5-thyminyl-5,6-dihydrothymine, a thymine dimer which is also called the spore photoproduct (SP), in germinating endospores. SPL is a radical S-adenosylmethionine (SAM) enzyme, utilizing the 5′-deoxyadenosyl radical generated by SAM reductive cleavage reaction to revert SP to two thymine residues. Here we review the current progress in SPL mechanistic studies. Protein radicals are known to be involved in SPL catalysis; however, how these radicals are quenched to close the catalytic cycle is under debate.