4-deoxy-4-sulfo-D-erythrulose + D-glyceraldehyde 3-phosphate <=> sulfoacetaldehyde + D-xylulose 5-phosphate
4-deoxy-4-sulfo-d-erythrulose + d-glyceraldehyde 3-phosphate <=> sulfoacetaldehyde + d-xylulose 5-phosphate