6JYJ

Crystal structure of FAM46B (TENT5B)

6JYJ の概要

• エントリーDOI: 10.2210/pdb6jyj/pdb
• 分子名称: Terminal nucleotidyltransferase 5B, CITRATE ANION (3 entities in total)
• 機能のキーワード: fam46b(tent5b);fam46(tent5);poly(a)polymerase;, gene regulation
• 由来する生物種: Xenopus tropicalis (Western clawed frog)
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 138506.54

構造登録者

Zhang, H.,Hu, J.L.,Gao, S. (登録日: 2019-04-26, 公開日: 2020-03-04, 最終更新日: 2024-04-03)

主引用文献

Hu, J.L.,Liang, H.,Zhang, H.,Yang, M.Z.,Sun, W.,Zhang, P.,Luo, L.,Feng, J.X.,Bai, H.,Liu, F.,Zhang, T.,Yang, J.Y.,Gao, Q.,Long, Y.,Ma, X.Y.,Chen, Y.,Zhong, Q.,Yu, B.,Liao, S.,Wang, Y.,Zhao, Y.,Zeng, M.S.,Cao, N.,Wang, J.,Chen, W.,Yang, H.T.,Gao, S.
FAM46B is a prokaryotic-like cytoplasmic poly(A) polymerase essential in human embryonic stem cells.
Nucleic Acids Res., 48:2733-2748, 2020

PubMed Abstract: Family with sequence similarity (FAM46) proteins are newly identified metazoan-specific poly(A) polymerases (PAPs). Although predicted as Gld-2-like eukaryotic non-canonical PAPs, the detailed architecture of FAM46 proteins is still unclear. Exact biological functions for most of FAM46 proteins also remain largely unknown. Here, we report the first crystal structure of a FAM46 protein, FAM46B. FAM46B is composed of a prominently larger N-terminal catalytic domain as compared to known eukaryotic PAPs, and a C-terminal helical domain. FAM46B resembles prokaryotic PAP/CCA-adding enzymes in overall folding as well as certain inter-domain connections, which distinguishes FAM46B from other eukaryotic non-canonical PAPs. Biochemical analysis reveals that FAM46B is an active PAP, and prefers adenosine-rich substrate RNAs. FAM46B is uniquely and highly expressed in human pre-implantation embryos and pluripotent stem cells, but sharply down-regulated following differentiation. FAM46B is localized to both cell nucleus and cytosol, and is indispensable for the viability of human embryonic stem cells. Knock-out of FAM46B is lethal. Knock-down of FAM46B induces apoptosis and restricts protein synthesis. The identification of the bacterial-like FAM46B, as a pluripotent stem cell-specific PAP involved in the maintenance of translational efficiency, provides important clues for further functional studies of this PAP in the early embryonic development of high eukaryotes.

PubMed: 32009146
DOI: 10.1093/nar/gkaa049

実験手法

X-RAY DIFFRACTION (2.69319882982 Å)