多利醇
内质网
糖基化
化学
转移酶
糖基转移酶
糖生物学
磷酸转移酶
肽聚糖
生物化学
核苷酸糖
细胞生物学
酶
生物
生物合成
糖蛋白
聚糖
作者
Christine Noffz,Sabine Keppler-Ross,Neta Dean
出处
期刊:Glycobiology
[Oxford University Press]
日期:2009-01-07
卷期号:19 (5): 472-478
被引量:42
标识
DOI:10.1093/glycob/cwp001
摘要
N-Linked glycosylation begins with the formation of a dolichol-linked oligosaccharide in the endoplasmic reticulum (ER). The first two steps of this pathway lead to the formation of GlcNAc(2)-PP-dolichol, whose synthesis is sequentially catalyzed by the Alg7p GlcNAc phosphotransferase and by the dimeric Alg13p/Alg14p UDP-GlcNAc transferase on the cytosolic face of the endoplasmic reticulum. Here, we show that the Alg7p, Alg13p, and Alg14p glycosyltransferases form a functional multienzyme complex. Coimmunoprecipitation and gel filtration assays demonstrate that the Alg7p/Alg13p/Alg14p complex is a hexamer with a native molecular weight of approximately 200 kDa and an Alg7p:Alg13:Alg14p stoichiometry of 1:1:1. These results highlight and extend the striking parallels that exist between these eukaryotic UDP-GlcNAc transferases and their bacterial MraY and MurG homologs that catalyze the first two steps of the lipid-linked peptidoglycan precursor. In addition to their preferred substrate and lipid acceptors, these enzymes are similar in their structure, chemistry, temporal, and spatial organization. These similarities point to an evolutionary link between the early steps of N-linked glycosylation and those of peptidoglycan synthesis.
科研通智能强力驱动
Strongly Powered by AbleSci AI