Heterologous production and characterization of the C7-cyclitol kinase ValC. A) SDS-PAGE analysis of His6-tagged ValC protein. Lanes: 1, molecular weight marker; 2, soluble protein of extract of E. coli BL21 Gold(DE3)pLysS/pTMVC-1 before induction; 3, total protein of extract of E. coli BL21 Gold(DE3)pLysS/pTMVC-1 after induction with IPTG; 4, soluble protein of lane 3; 5, purified His6-tagged ValC; B) Thin-layer chromatography analyses of ValC assay mixtures (solvent system, n-butanol:ethanol:water, 9:7:4). Lanes: 1, ValC without substrate; 2, ValC with 2-epi-5-epi-valiolone and ATP; 3, ValC with 5-epi-valiolone and ATP; 4, ValC with valienone and ATP; 5, ValC with validone and ATP; 6, Boiled ValC with valienone and ATP; 7, ValC with valienone and ATP; 8, ValC with valienone without ATP; 9, ValC with d-glucose and ATP; 10, ValC with d-glucose without ATP; C) and D) Partial 1H NMR spectra of valienone and valienone 7-phosphate measured on a Bruker DPX-300.