Salvage of the thiamin pyrimidine moiety by plant TenA proteins lacking an active-site cysteine
作者:Rémi Zallot、Mohammad Yazdani、Aymeric Goyer、Michael J. Ziemak、Jiahn-Chou Guan、Donald R. McCarty、Valérie de Crécy-Lagard、Svetlana Gerdes、Timothy J. Garrett、Jordi Benach、John F. Hunt、David K. Shintani、Andrew D. Hanson
DOI:10.1042/bj20140522
日期:2014.10.1
cysteine, the other (TenA_E) not. TenA_C proteins participate in thiamin salvage by hydrolysing the thiamin breakdown product amino-HMP (4-amino-5-aminomethyl-2-methylpyrimidine) to HMP (4-amino-5-hydroxymethyl-2-methylpyrimidine); the function of TenA_E proteins is unknown. Comparative analysis of prokaryote and plant genomes predicted that (i) TenA_E has a salvage role similar to, but not identical with
TenA 蛋白家族存在于原核生物、植物和真菌中;它有两个亚家族,一个 (TenA_C) 具有活性位点半胱氨酸,另一个 (TenA_E) 没有。TenA_C 蛋白通过将硫胺分解产物氨基-HMP (4-amino-5-aminomethyl-2-methylpyrimidine) 水解为 HMP (4-amino-5-hydroxymethyl-2-methylpyrimidine) 参与硫胺回收;TenA_E 蛋白的功能未知。原核生物和植物基因组的比较分析预测 (i) TenA_E 具有与 TenA_C 相似但不相同的补救作用,以及 (ii) TenA_E 和 TenA_C 也具有非补救作用,因为它们存在于不能制造硫胺素。重组拟南芥和玉米 TenA_E 蛋白 (At3g16990, GRMZM2G080501) 将氨基 HMP 水解为 HMP,并且更积极地将氨基 HMP 的 N-甲酰基衍生物水解为氨基