(A) Nomura ribosome assembly map. (B) Experimental setup: 400 nM unlabeled S7, 100 nM Cy5-S3 and 400 nM all other unlabeled 3’domain r-proteins were injected; 35 °C. (C) All r-proteins binding upstream of S3 are required for stable S3 binding. Number of molecules analyzed in (C) (n) = 505, 1017, 924, 2699, 1453. See also Figures S6, S7 and Data S2.