Figure 5.
Decoding the molecular organization of Get3/4/5complex. (A) MS/MS spectra of (Get3)2(Get4)2(Get5)2. CID of the (Get3)2(Get4)2(Get5)2 produced two sets of subcomplexes. Peaks in purple highlight the subcomplexes generated by the loss of a monomeric Get4 unit from the overall complex. The remainder of the trimer (Get3)2-Get4-(Get5)2 species was observed at the higher m/z range (purple peaks in the right panel). The lost, monomeric Get4 molecule was detected in the lower m/z region (purple peaks in the left panel). Peaks in blue highlight the subcomplexes generated by the loss of a monomeric Get5 unit from the overall complex. The remainder of the trimer (Get3)2-(Get4)2-Get5 species was observed at the higher m/z range (blue peaks on the right-hand side). The lost, monomeric Get5 molecule was detected in the lower m/z region (blue peaks in the left panel). (B) Subcomplexes (Get3)2(Get4) (Get5)2 and Get4 can be produced by CID of parent ions with molecular organization presented in both Scheme II and III but not in Scheme I. (C) In contrast, subcomplexes (Get3)2(Get4)2(Get5) and Get5 can be produced by CID of parent ions with molecular organization presented in the Scheme I and II but not in Scheme III. Altogether the data showed that only fragmentation of (Get3)2(Get4)2(Get5)2 with molecular organization presented in Scheme II can give the fragmentation pattern shown in panel A. Dotted lines on parent ions indicate interaction interfaces destroyed in CID during generation of fragment ions. Similar spectra were obtained for three independent protein preparations.