Extended Data Figure 8: HPLC-MS analysis of OxyBtei-catalysed cyclization of peptides presented by mutant variants of PCP7–X.
From: X-domain of peptide synthetases recruits oxygenases crucial for glycopeptide biosynthesis
a–d, Representative HPLC-MS chromatograms of in vitro OxyBtei turnover reactions with substrate heptapeptide Tei7(Hpg3,7) bound to the different GB1–PCP7–X mutants (X1: R167A, R171A (a); X2: E290A, D291A (b); X3: E377A, R382A (c); X1–3: R167A, R171A, E290A, D291A, E377A, R382A (d)). Occurrence of ions corresponding to the singly charged, linear peptide (hydrolysed m/z 1,088, methylhydrazide m/z 1,116) and the crosslinked monocyclic product (hydrolysed m/z 1,086, methylhydrazide m/z 1,114) were recorded using SIM in negative mode. The origins of the multiple peaks observed for each mass are described in Extended Data Fig. 7.
