Structural basis for ubiquitin recognition by a novel domain from human phospholipase A2-activating protein.
Ubiquitin (Ub) is an essential modifier conserved in all eukaryotes from yeast to human. Phospholipase A(2)-activating protein (PLAA), a mammalian homolog of yeast DOA1/UFD3, has been proposed to be able to bind with Ub, which plays important roles in endoplasmic reticulum-associated degradation, vesicle formation, and DNA damage response. We have identified a core domain from the PLAA family ubiquitin-binding region of human PLAA (residues 386-465, namely PFUC) that can bind Ub and elucidated its solution structure and Ub-binding mode by NMR approaches. The PFUC domain possesses equal population of two conformers in solution by cis/trans-isomerization, whereas the two isomers exhibit almost equivalent Ub binding abilities. This domain structure takes a novel fold consisting of four beta-strands and two alpha-helices, and the Ub-binding site on PFUC locates in the surface of alpha2-helix, which is to some extent analogous to those of UBA, CUE, and UIM domains. This study provides structural basis and biochemical information for Ub recognition of the novel PFU domain from a PLAA family protein that may connect ubiquitination and degradation in endoplasmic reticulum-associated degradation.
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Qing-Shan
QS
Fu
Chen-Jie
CJ
Zhou
Hong-Chang
HC
Gao
Ya-Jun
YJ
Jiang
Zi-Ren
ZR
Zhou
Jing
J
Hong
Wen-Ming
WM
Yao
Ai-Xin
AX
Song
Dong-Hai
DH
Lin
Hong-Yu
HY
Hu
D000595:Amino Acid Sequence; D000818:Animals; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D025801:Ubiquitin / Q000737:chemistry*
D011506:Proteins; D025801:Ubiquitin; C055324:phospholipase A2-activating protein; D005982:Glutathione Transferase