[ThiS sulfur-carrier protein]-C-terminal-Gly-aminoethanethioate + 2-iminoacetate + 1-deoxy-D-xylulose 5-phosphate = [ThiS sulfur-carrier protein]-C-terminal Gly-Gly + 2-[(2R,5Z)-2-carboxy-4-methylthiazol-5(2H)-ylidene]ethyl phosphate + 2 H2O + H(+) — reaction