Structure and visualization of STAT1. (A) Schematic representation of the STAT1 wild-type and the truncated mutant. N, N domain; CC, coiled coil domain; NES, nuclear export signal; DBD, DNA-binding domain; L, linker domain; SH2, Src homology 2 domain; TAD, transactivation domain. (B) wt-STAT1 molecules (red) and nuclear envelope labeled by NTF2-AF488 (green) in a microinjected HeLa cell. Field size: (12.2 μm)2. (C) Sequence of 20 magnified consecutive image sections of a single wt-STAT1 molecule in the cell nucleus. Frame rate: 191.6 Hz; field size: (2.5 μm)2. (D) Complete trajectory of the wt-STAT1 molecule shown in C; the color code is according to the frame number in C.