Fig. 2
From: Metabolic engineering of Escherichia coli for de novo biosynthesis of vitamin B12

The CBAD biosynthetic pathway and LC–MS detection of biosynthetic intermediates. a HBA is converted to CBAD by CobB and the CobN,S,T enzymes. b The strain FH131 expressing cobB converted HBA to HBAD, as assessed by HPLC. c Comparison of mass spectra for HBAD from the FH001 and FH131 stains. d Comparison of mass spectra for CBAD from recombinant E. coli stains with or without the expression of the cbiM,N,Q,O proteins