| Structural highlights
7ad9 is a 15 chain structure with sequence from Oryctolagus cuniculus, Saccharomyces cerevisiae and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | Electron Microscopy, Resolution 3.5Å |
| Ligands: | , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
AB140_YEAST S-adenosyl-L-methionine-dependent methyltransferase that mediates N(3)-methylcytidine modification of residue 32 of the tRNA anticodon loop of tRNA(Thr) and tRNA(Ser) (PubMed:21518804, PubMed:21518805, PubMed:28003514). N(3)-methylcytidine methylation of tRNA(Thr) requires the N6-threonylcarbamoylation of tRNA (t6A37) by the EKC/KEOPS complex as prerequisite (PubMed:28003514). N(3)-methylcytidine methylation of tRNA(Ser) requires the formation of N(6)-dimethylallyladenosine(37) (i6A37) by MOD5 as prerequisite (PubMed:28003514). Methylation of tRNA(Ser) is also stimulated by SES1 (PubMed:28003514). Binds F-actin and shows weak F-actin cross-linking activity (PubMed:9467951).[1] [2] [3] [4]
Publication Abstract from PubMed
Lifeact is a short actin-binding peptide that is used to visualize filamentous actin (F-actin) structures in live eukaryotic cells using fluorescence microscopy. However, this popular probe has been shown to alter cellular morphology by affecting the structure of the cytoskeleton. The molecular basis for such artefacts is poorly understood. Here, we determined the high-resolution structure of the Lifeact-F-actin complex using electron cryo-microscopy (cryo-EM). The structure reveals that Lifeact interacts with a hydrophobic binding pocket on F-actin and stretches over 2 adjacent actin subunits, stabilizing the DNase I-binding loop (D-loop) of actin in the closed conformation. Interestingly, the hydrophobic binding site is also used by actin-binding proteins, such as cofilin and myosin and actin-binding toxins, such as the hypervariable region of TccC3 (TccC3HVR) from Photorhabdus luminescens and ExoY from Pseudomonas aeruginosa. In vitro binding assays and activity measurements demonstrate that Lifeact indeed competes with these proteins, providing an explanation for the altering effects of Lifeact on cell morphology in vivo. Finally, we demonstrate that the affinity of Lifeact to F-actin can be increased by introducing mutations into the peptide, laying the foundation for designing improved actin probes for live cell imaging.
Structure of the Lifeact-F-actin complex.,Belyy A, Merino F, Sitsel O, Raunser S PLoS Biol. 2020 Nov 20;18(11):e3000925. doi: 10.1371/journal.pbio.3000925. , eCollection 2020 Nov. PMID:33216759[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ D'Silva S, Haider SJ, Phizicky EM. A domain of the actin binding protein Abp140 is the yeast methyltransferase responsible for 3-methylcytidine modification in the tRNA anti-codon loop. RNA. 2011 Jun;17(6):1100-10. PMID:21518804 doi:10.1261/rna.2652611
- ↑ Noma A, Yi S, Katoh T, Takai Y, Suzuki T, Suzuki T. Actin-binding protein ABP140 is a methyltransferase for 3-methylcytidine at position 32 of tRNAs in Saccharomyces cerevisiae. RNA. 2011 Jun;17(6):1111-9. PMID:21518805 doi:10.1261/rna.2653411
- ↑ Han L, Marcus E, D'Silva S, Phizicky EM. S. cerevisiae Trm140 has two recognition modes for 3-methylcytidine modification of the anticodon loop of tRNA substrates. RNA. 2017 Mar;23(3):406-419. PMID:28003514 doi:10.1261/rna.059667.116
- ↑ Asakura T, Sasaki T, Nagano F, Satoh A, Obaishi H, Nishioka H, Imamura H, Hotta K, Tanaka K, Nakanishi H, Takai Y. Isolation and characterization of a novel actin filament-binding protein from Saccharomyces cerevisiae. Oncogene. 1998 Jan 8;16(1):121-30. PMID:9467951 doi:10.1038/sj.onc.1201487
- ↑ Belyy A, Merino F, Sitsel O, Raunser S. Structure of the Lifeact-F-actin complex. PLoS Biol. 2020 Nov 20;18(11):e3000925. PMID:33216759 doi:10.1371/journal.pbio.3000925
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