Extended Data Fig. 10: Detection of ThiC unique peptides in the forward and reverse orientation.
From: Intragenic DNA inversions expand bacterial coding capacity
(A) Schematic showing the ThiC protein sequence in the forward and predicted reverse open reading frames (ORF1, ORF2, ORF3). Arrows indicate the direction of transcription. Shared colors between the forward and reverse ORFs indicate identical amino acids. The dark orange box in ORF1 is the ThiC reverse specific peptide. (B) Mass spectrometry quantification, by data-independent acquisition, of ThiC tryptic peptides aligned with each ORF. NCPVPVGTVPIYQALEK includes cysteine carbamidomethylation. (C) Quantification of the unique ThiC tryptic peptides that align exclusively to the forward or reverse sequences. Representative extracted ion chromatograms show the identified fragment ions applied in the quantification of the forward and reverse peptides, as detected in WT and LR, respectively. Representative MS/MS spectra of the unique ThiC forward peptide GDVEQLPEITSEYGQMR detected in WT and unique ThiC predicted inverton peptide GDVEQLPEITSEYGQIR detected in LR. Spectra include the MS1 precursor ion (orange), as well as b- and y- fragment ions (blue and red, respectively). ND, not detected; WT, wild-type; LF, locked forward thiC intragenic inverton; UF, unlocked forward thiC intragenic inverton; LR, locked reverse thiC intragenic inverton; UR, unlocked reverse thiC intragenic inverton.
