Tumor development of human takes multiple steps o-ver a long period of time.The multiple steps with DNAmutations on gene......

生物体内的蛋氨酸合成酶（ｍｅｔｈｉｏｎｉｎｅ ｓｙｎｔｈａｓｅ）以Ｎ＾５－甲基四氢叶酸作为辅酶，通过两步ＳＮ２反应，将甲基转移到高胱氨酸的巯基上生成蛋氨酸。该酶起到中间甲基载体的......