5il0
Crystal structural of the METTL3-METTL14 complex for N6-adenosine methylation
Structural highlights
FunctionMTA70_HUMAN N6-methyltransferase that methylates adenosine residues of some RNAs and acts as a regulator of the circadian clock, differentiation of embryonic stem cells and primary miRNA processing. N6-methyladenosine (m6A), which takes place at the 5'-[AG]GAC-3' consensus sites of some mRNAs, plays a role in the efficiency of mRNA splicing, processing, translation efficiency, editing and mRNA stability (PubMed:22575960, PubMed:24284625, PubMed:25719671, PubMed:25799998, PubMed:26321680, PubMed:26593424, PubMed:9409616). M6A regulates the length of the circadian clock: acts as a early pace-setter in the circadian loop by putting mRNA production on a fast-track for facilitating nuclear processing, thereby providing an early point of control in setting the dynamics of the feedback loop (By similarity). M6A also acts as a regulator of mRNA stability: in embryonic stem cells (ESCs), m6A methylation of mRNAs encoding key naive pluripotency-promoting transcripts results in transcript destabilization, promoting differentiation of ESCs (By similarity). M6A also takes place in other RNA molecules, such as primary miRNA (pri-miRNAs) (PubMed:25799998). Mediates methylation of pri-miRNAs, marking them for recognition and processing by DGCR8 (PubMed:25799998).[UniProtKB:Q8C3P7][1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedChemical modifications of RNA have essential roles in a vast range of cellular processes. N(6)-methyladenosine (m(6)A) is an abundant internal modification in messenger RNA and long non-coding RNA that can be dynamically added and removed by RNA methyltransferases (MTases) and demethylases, respectively. An MTase complex comprising methyltransferase-like 3 (METTL3) and methyltransferase-like 14 (METTL14) efficiently catalyses methyl group transfer. In contrast to the well-studied DNA MTase, the exact roles of these two RNA MTases in the complex remain to be elucidated. Here we report the crystal structures of the METTL3-METTL14 heterodimer with MTase domains in the ligand-free, S-adenosyl methionine (AdoMet)-bound and S-adenosyl homocysteine (AdoHcy)-bound states, with resolutions of 1.9, 1.71 and 1.61 A, respectively. Both METTL3 and METTL14 adopt a class I MTase fold and they interact with each other via an extensive hydrogen bonding network, generating a positively charged groove. Notably, AdoMet was observed in only the METTL3 pocket and not in METTL14. Combined with biochemical analysis, these results suggest that in the m(6)A MTase complex, METTL3 primarily functions as the catalytic core, while METTL14 serves as an RNA-binding platform, reminiscent of the target recognition domain of DNA N(6)-adenine MTase. This structural information provides an important framework for the functional investigation of m(6)A. Structural basis of N(6)-adenosine methylation by the METTL3-METTL14 complex.,Wang X, Feng J, Xue Y, Guan Z, Zhang D, Liu Z, Gong Z, Wang Q, Huang J, Tang C, Zou T, Yin P Nature. 2016 May 25;534(7608):575-8. doi: 10.1038/nature18298. PMID:27281194[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
