5bmu
From Proteopedia
The crystal structure of the GST-like domains complex of AIMP3-EPRS mutant C92SC105SC123S
Structural highlights
Function[MCA3_HUMAN] Positive modulator of ATM response to DNA damage. [SYEP_HUMAN] Catalyzes the attachment of the cognate amino acid to the corresponding tRNA in a two-step reaction: the amino acid is first activated by ATP to form a covalent intermediate with AMP and is then transferred to the acceptor end of the cognate tRNA. Component of the GAIT (gamma interferon-activated inhibitor of translation) complex which mediates interferon-gamma-induced transcript-selective translation inhibition in inflammation processes. Upon interferon-gamma activation and subsequent phosphorylation dissociates from the multisynthetase complex and assembles into the GAIT complex which binds to stem loop-containing GAIT elements in the 3'-UTR of diverse inflammatory mRNAs (such as ceruplasmin) and suppresses their translation.[1] [2] [3] Publication Abstract from PubMedMany multi-component protein complexes mediating diverse cellular processes are assembled through scaffolds with specialized protein interaction modules. The multi-tRNA synthetase complex (MSC), consisting of nine different aminoacyl-tRNA synthetases and three non-enzymatic factors (AIMP1-3), serves as a hub for many signaling pathways in addition to its role in protein synthesis. However, the assembly process and structural arrangement of the MSC components are not well understood. Here we show the heterotetrameric complex structure of the glutathione transferase (GST) domains shared among the four MSC components, methionyl-tRNA synthetase (MRS), glutaminyl-prolyl-tRNA synthetase (EPRS), AIMP2 and AIMP3. The MRS-AIMP3 and EPRS-AIMP2 using interface 1 are bridged via interface 2 of AIMP3 and EPRS to generate a unique linear complex of MRS-AIMP3:EPRS-AIMP2 at the molar ratio of (1:1):(1:1). Interestingly, the affinity at interface 2 of AIMP3:EPRS can be varied depending on the occupancy of interface 1, suggesting dynamic nature of the linear GST tetramer. The four components are optimally arranged for maximal accommodation of additional domains and proteins. These characteristics suggest the GST tetramer as a unique and dynamic structural platform from which the MSC components are assembled. Considering prevalence of the GST-like domains, this tetramer can also provide a tool for the communication of the MSC with other GST-containing cellular factors. Assembly of Multi-tRNA Synthetase Complex via Heterotetrameric Glutathione Transferase-Homology Domains.,Cho HY, Maeng SJ, Cho HJ, Choi YS, Chung JM, Lee S, Kim HK, Kim JH, Eom CY, Kim YG, Guo M, Jung HS, Kang BS, Kim S J Biol Chem. 2015 Oct 15. pii: jbc.M115.690867. PMID:26472928[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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