Terminally truncated isopenicillin N synthase generates a dithioester product: evidence for a thioaldehyde intermediate during catalysis and a new mode of reaction for non-heme iro... by McNeill, LA, Brown, TJN, Sami, M, Clifton, IJ, Burzlaff, NI, Claridge, TDW, Adlington, RM, Baldwin, JE, Rutledge, PJ, Schofield, CJ