ivan47

Thank you for the explanation. Here's a bit of a stretch, now: What size protein might make it through the cell-wall? I ask because I'm looking at some open-source protein design software and wondering whether it might be possible to target the GT chain active site in the TF-GT complex (transferase-glycosyltransferase) with some high-affinity protein as recommended by authors (except with a protein as opposed to a typical antibiotic) .

It's "very easy" for someone who has background in biology. Mine is in computer science and math, so a direct answer would be helpful. Anyway, I guess you're saying it looks like this (could you confirm?): OUTSIDE CELL ============ (Cell wall) PBP2 --------------------membrane cytoplasm PBP2 is bound to the membrane but acts upon the cell wall. I didn't realize membrane and cell wall were separate entities in bacteria, I only knew that about plants. So for something like penicillin to function, does it then have to be absorbed through the cell wall?

Hopefully this is a quickie for someone who knows more about bio than I do. PBP2, which is a membrane-bound protein in methicillin-resistant Staphylococcus aureus (MRSA) and other bacteria catalyzes linking of peptidoglycans. Which side of the cell membrane/wall does the exposed part of the protein reside on (cytoplasm, or outside)? The diagrams don't say and my background is not in biology. The paper I'm looking at is here: http://www.sciencemag.org/cgi/content/full/315/5817/1402 Thanks for your help.