产品内容
本酶催化的反应为(1) 2 ATP + 2 Cob(II)alamin + A Reduced Flavoprotein = 2 Triphosphate + 2 Adenosylcob(III)alamin + An Oxidized Flavoprotein (Overall Reaction);;(1a) 2 Cob(II)alamin + 2 [Corrinoid Adenosyltransferase] = 2 [Corrinoid Adenosyltransferase]-Cob(II)alamin;;(1b) A Reduced Flavoprotein + 2 [Corrinoid Adenosyltransferase]-Cob(II)alamin = An Oxidized Flavoprotein + 2 [Corrinoid Adenosyltransferase]-Cob(I)alamin (Spontaneous);;(1c) 2 ATP + 2 [Corrinoid Adenosyltransferase]-Cob(I)alamin = 2 Triphosphate + 2 Adenosylcob(III)alamin + 2 [Corrinoid Adenosyltransferase];;(2) 2 ATP + 2 Cob(II)yrinic Acid A,c-Diamide + A Reduced Flavoprotein = 2 Triphosphate + 2 Adenosylcob(III)yrinic Acid A,c-Diamide + An Oxidized Flavoprotein (Overall Reaction);;(2a) 2 Cob(II)yrinic Acid A,c-Diamide + 2 [Corrinoid Adenosyltransferase] = 2 [Corrinoid Adenosyltransferase]-Cob(II)yrinic Acid A,c-Diamide;;(2b) A Reduced Flavoprotein + 2 [Corrinoid Adenosyltransferase]-Cob(II)yrinic Acid A,c-Diamide = An Oxidized Flavoprotein + 2 [Corrinoid Adenosyltransferase]-Cob(I)yrinic Acid A,c-Diamide (Spontaneous);;(2c) 2 ATP + 2 [Corrinoid Adenosyltransferase]-Cob(I)yrinic Acid A,c-Diamide = 2 Triphosphate + 2 Adenosylcob(III)yrinic Acid A,c-Diamide + 2 [Corrinoid Adenosyltransferase]，系统名称为ATP:cob(II)alamin Cobeta-Adenosyltransferase，咕啉腺苷化途径包括三个步骤：（i）通过单电子转移将咕啉内的 Co(III) 还原为 Co(II)。这可在二氢黄素核苷酸或还原型黄素蛋白存在下非酶促发生 [3]。（ii）Co(II) 被咕啉腺苷转移酶结合，导致下轴配体被芳香族残基置换。与游离化合物相比，4 配位 Co(II) 中间体的还原电位升高约 250 mV，使其达到生理范围。随后发生来自游离二氢黄素或黄素蛋白还原型黄素辅因子的第二次单电子转移，导致还原为 Co(I) [7]。（iii）Co(I) 对 ATP 的腺苷部分进行亲核攻击，导致脱氧腺苷基转移并将钴原子氧化为 Co(III) 状态。已描述了三种序列上不相关的咕啉腺苷转移酶。在厌氧菌肠道沙门氏菌（Salmonella enterica）中，它们分别由 cobA 基因（参与腺苷钴胺素从头生物合成和补救的持家酶）、pduO 基因（参与 (S)-丙烷-1,2-二醇利用）和 eutT 基因（参与乙醇胺利用）编码。由于 EutT 在催化过程中将三磷酸水解为二磷酸和磷酸，它被归类为单独的酶。哺乳动物酶属于 PduO 型。该酶可作用于其他咕啉类化合物，如 cob(II)inamide。
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