(A) Schematic of human TRMT1 primary structure with predicted Nsp5 cleavage site. Mitochondrial targeting signal (MTS), methyltransferase (MT) domain, and zinc finger motif are denoted. (B) Consensus sequence logo of cleavage sites in SARS-CoV-2 polyproteins. (C) Alpha-fold predicted structure of human TRMT1 with putative Nsp5 cleavage site denoted in magenta and arrowhead. (D) Immunoblot of input and strep-tactin purifications from human cells expressing empty vector, wild-type (WT) Nsp5, or Nsp5-C145A fused to the Strep-tag without or with co-expression with TRMT1-FLAG. The immunoblot was probed with anti-Strep, FLAG, and actin antibodies. Square represents TRMT1-FLAG, circle represents endogenous TRMT1. Size markers are noted to the left in kiloDalton. The experiment in (D) was repeated as an independent biological replicate in Figure 2—figure supplement 1.
Figure 2—source data 1. Raw uncropped immunoblots for Figure 2D.