WDR4

Non-catalytic component of the METTL1-WDR4 methyltransferase complex required for the formation of N(7)-methylguanine in a subset of RNA species, such as tRNAs, mRNAs and microRNAs (miRNAs). In the METTL1-WDR4 methyltransferase complex, WDR4 acts as a scaffold for tRNA-binding. Required for the formation of N(7)-methylguanine at position 46 (m7G46) in a large subset of tRNAs that contain the 5'-RAGGU-3' motif within the variable loop. M7G46 interacts with C13-G22 in the D-loop to stabilize tRNA tertiary structure and protect tRNAs from decay. Also required for the formation of N(7)-methylguanine at internal sites in a subset of mRNAs. Also required for methylation of a specific subset of miRNAs, such as let-7. Independently of METTL1, also plays a role in genome stability: localizes at the DNA replication site and regulates endonucleolytic activities of FEN1..

Function from UniProtKB (P57081), read 2026-09-23. CC BY 4.0.