Fig. 1.

Interaction among YabA, DnaA, and DnaN in vitro. (A) Zinc precipitation assay. Purified YabA (14 kDa), DnaA (51 kDa), and DnaN (42 kDa) proteins (a). YabA precipitation upon addition of Zn²⁺ (b) was assayed in the presence of DnaA or DnaN (c). Soluble fractions and precipitates were analyzed by Coomassie-stained 12.5% SDS/PAGE. (B) Cross-linking experiment among YabA, DnaA, and DnaN. Glutaraldehyde-cross-linked products were analyzed by silver-stained 12.5% SDS/PAGE. Without (lanes a–c) and with (lanes d–i) glutaraldehyde. Incubation of YabA with DnaA (lane e) or/and DnaN (lane h) gave rise to new high-molecular-weight (HMW) species (1, 2, and 3, respectively). Note that DnaN, which is a dimer in solution, was not cross-linked under the conditions used.