Figure 2

MS/MS spectra of peptides uniquely identifying hNaa15p and hNaa16p in complex with hNaa10p. A. MS/MS spectrum of the peptide RAIELATTLDESLTNR, which uniquely identifies hNaa15p in the hNaa10p affinity extraction. The MS/MS spectrum of the +2 peptide ion was matched to this sequence with an Xcorr of 4.25 [30]; the peptide had a probability of correct sequencing of 0.99 [32]. B. MS/MS spectrum of the peptide DLESFNEDFLK, which uniquely identifies hNaa16p in the hNaa10p affinity extraction. The MS/MS spectrum of the +2 peptide ion was matched to this sequence with an Xcorr of 3.4; the peptide had a probability of correct sequencing of 0.95. All fragment ions have a +1 charge. Individual matched y ions (blue) and b ions (red) are indicated in bold; the position of the peptide precursor ion is indicated by the dagger; the x-axis units are m/z and the y-axis represents relative peak intensity normalized to the most intense fragment ion.