TY - JOUR
T1 - Structural insights into the high-efficiency catalytic mechanism of the sterileα-motif/histidine-aspartate domain-containing protein
AU - Li, Yanhong
AU - Kong, Jia
AU - Peng, Xin
AU - Hou, Wen
AU - Qin, Xiaohong
AU - Yu, Xiao Fang
N1 - Publisher Copyright:
© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2015/12/4
Y1 - 2015/12/4
N2 - Sterileα-motif/histidine-aspartate domain-containing protein (SAMHD1), a homo-tetrameric GTP/dGTP-dependent dNTP triphosphohydrolase, catalyzes the conversion of dNTP into deoxynucleoside and triphosphate. As the only characterized dNTP triphosphohydrolase in human cells, SAMHD1 plays an important role in human innate immunity, autoimmunity, and cell cycle control. Previous biochemical studies and crystal structures have revealed that SAMHD1 interconverts between an inactive monomeric or dimeric form and a dGTP/GTP-induced active tetrameric form. Here, we describe a novel state of SAMHD1(109-626 amino acids, SAMHD1C) that is characterized by a rapid initial hydrolysis rate. Interestingly, the crystal structure showed that this novel SAMHD1 tetramer contains only GTP and has structural features distinct from the GTP/dNTP-bound SAMHD1 tetramer. Our work thus reveals structural features of SAMHD1 that may represent one of its biological assembly states in cells.
AB - Sterileα-motif/histidine-aspartate domain-containing protein (SAMHD1), a homo-tetrameric GTP/dGTP-dependent dNTP triphosphohydrolase, catalyzes the conversion of dNTP into deoxynucleoside and triphosphate. As the only characterized dNTP triphosphohydrolase in human cells, SAMHD1 plays an important role in human innate immunity, autoimmunity, and cell cycle control. Previous biochemical studies and crystal structures have revealed that SAMHD1 interconverts between an inactive monomeric or dimeric form and a dGTP/GTP-induced active tetrameric form. Here, we describe a novel state of SAMHD1(109-626 amino acids, SAMHD1C) that is characterized by a rapid initial hydrolysis rate. Interestingly, the crystal structure showed that this novel SAMHD1 tetramer contains only GTP and has structural features distinct from the GTP/dNTP-bound SAMHD1 tetramer. Our work thus reveals structural features of SAMHD1 that may represent one of its biological assembly states in cells.
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U2 - 10.1074/jbc.M115.663658
DO - 10.1074/jbc.M115.663658
M3 - Article
C2 - 26438820
AN - SCOPUS:84948971961
SN - 0021-9258
VL - 290
SP - 29428
EP - 29437
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 49
ER -