Spectroscopic studies reveal details of substrate-induced conformational changes distant from the active site in isopenicillin N synthase by Rabe, P, Walla, CC, Goodyear, NK, Welsh, J, Southwart, R, Clifton, I, Linyard, JDS, Tumber, A, Claridge, TDW, Myers, WK, Schofield, CJ