Structural insight into how WDR4 promotes the tRNA N7-methylguanosine methyltransferase activity of METTL1.

The conformational change of METTL1 induced by WDR4 binding, especially in the vicinity of the SAM-binding pocket, indicated that WDR4 may affect the SAM-binding ability of METTL1. We further inspected the R170-interacting residues within the METTL1-WDR4 complex and found that R170 interacted extensively with other residues within the METTL1-WDR4 complex (Fig. First, METTL1 residues 107-112 (EIRVKV), which are important for SAM binding and recognition, formed an extended loop in the WDR4-bound state, instead of a short loop in apo or SAM-bound METTL1 (Fig. [Extracted from the article]