Fig. 1: Specific binding of AcpP to the neck region of MukB.

a Schematic of MukBEF in the elbow-bent configuration (left); structure of E. coli MukB^HN (right) using a crystal structure of the elbow (PDB 6H2X)¹¹, and a homology model based on H. ducreyi MukB^H structure (PBD 3EUK)⁵. The coiled-coil and joint are modeled and MukEF are shown in cartoon form (note that the C- and N-terminal domains of a given MukF monomer normally contact different MukB monomers). Structures of AcpP-PPant are also shown (bottom, left, PBD 3NY7)⁵⁸. b Schematic of MukB truncations. c SDS-PAGE analysis of AcpP co-purification with MukB truncations. Putative disulfide-linked MukB–AcpP species are indicated with an asterisk. Note that AcpP (MW 8640 Da) runs with an apparent MW of ~18,000 Da on SDS-PAGE. The gel is representative of at least two independent experiments. d–f nMS analysis of AcpP–MukB truncation interactions. d MukB^H with the addition of recombinant AcpP (mixed population of apo and holo species), ^†difference of 131 Da suggests N-terminal Met excision. e MukB^N with co-purified AcpP and f MukB^HN with co-purified AcpP. Theoretical masses in parentheses. ^‡An averaged mass of apo- and holo-AcpP was used in the theoretical mass calculations. In samples containing native AcpP, at least two different species were identified, likely representing different posttranslational modifications of AcpP. Source data are provided as a Source Data file.