Interaction of the bZIP basic domain of N330 with p65. (A) Sequential 10-aa deleted N-terminal fragments from aa's 330 to 266 are indicated by lines under the schematic of N330 in which the PYRIN domain (PYD) and bZIP basic domain (bZIP) reside. The first and last aa numbers of bZIP basic domain are indicated on the top. (B) PT67 cells were cotransfected with p65-V5 and the 10-aa deleted N-terminal fragments depicted in panel A. Lysates were immunoprecipitated with antimyc Ab followed by Western blotting with anti-V5 (middle) and antimyc (bottom) Abs. Expression of p65-V5 in whole lysates is shown by anti-V5 Ab (top). (C) HeLa cells were cotransfected with p65-V5 and the 10-aa deleted N-terminal fragments depicted in panel A. From the nuclear lysates, NF-κB DNA-binding activity was measured by EMSA as in Figure 3A.