Figure 4

Schematic of phosphorylated proteins within Mycoplasma pneumoniae overlaid on a diagram of the hypothesized complex terminal organelle and cytoskeleton-like structure. "Phos (+)" means the protein has been identified as phosphorylated in our data or previous studies. "Phos (+?)" means there is weak experimental evidence published supporting phosphorylation, and "(?)" means there is no evidence regarding phosphorylation, but that the protein was localized by immunofluorescence studies to the cytoskeleton-like structure. All protein locations are represented based upon the presently available literature data, but may be subject to change based upon further studies. For proteins labeled with "(~)", conflicting evidence indicates that they may have multiple locations in the cell. The localization of proteins were determined as follows: HMW1, HMW2 and HMW3 were shown essential in the electron-dense core of the terminal organelle in M. pneumoniae, though HMW3 may also have other cellular locations; P30 and P65 are localized at the surface of the distal end of the terminal organelle [38, 39]; P1, P90 and P40 are known to interact, with P1 penetrating the cell membrane, anchored to cytoskeletal structures by P90 and P40 [41]; and in a cross-linked protein complex with the P1 adhesin of M. pneumoniae, it appears that DnaK might be involved in translocation of proteins from cytoplasm to the membrane. Pyruvate dehydrogenase is implicated as a structural protein in the attachment organelle [41]. EF-Tu is a putative cytoskeletal element in E. coli [45], but has also been associated with translation so it may have multiple functions and hence locations. It, along with DnaK and pyruvate dehydrogenase, have previously been shown involved in the filamentous network. [41, 45]