Cryo-EM structure of human lysosomal cobalamin exporter ABCD4  

作　　者：Da Xu Zhang Feng Wen-Tao Hou Yong-Liang Jiang Liang Wang Linfeng Sun Cong-Zhao Zhou Yuxing Chen 

机构地区：[1]Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences,University of Science and Technology of China,230027 Hefei,Anhui,China [2]CAS Centre for Excellence in Molecular Cell Science,University of Science and Technology of China,230027 Hefei,Anhui,China

出　　处：《Cell Research》2019年第12期1039-1041,共3页细胞研究（英文版）

基　　金：the Ministry of Science and Technology of China(2015CB910103);the Chinese Academy of Science(XDB08020304);the National Natural Science Foundation of China(31621002);the Fundamental Research Funds for the Central Universities(WK2070000117).

摘　　要：Dear Editor,Cobalamin,also known as vitamin B12,can only be biosynthesized by certain bacteria and archaea.As an essential nutrient for humans,it should be obtained from daily food.1 Exogenous cobalamin is taken up by the cell through an endocytosis process,then released into the lysosome as a free form,and finally pumped out to the cytosol for utilization.2 The human ATP-binding cassette(ABC)transporter ABCD4 localized on lysosomal membrane is indispensable for the efflux of cobalamin from lysosome to cytosol.3 Mutations in ABCD4 gene may result in cobalamin deficiency and inborn diseases.The patients suffer from combined symptoms:hypotonia,lethargy,poor feeding,bone marrow suppression,macrocytic anemia,and heart defects.3 However,the absence of the structure of human ABCD4 limits our understanding of the molecular mechanism of pathogenesis.

关 键 词：VITAMIN STRUCTURE finally 

分 类 号：R73[医药卫生—肿瘤]