Trp157 and Thr591 are evolutionarily conserved residues. (A) Mutations implicated in combined VKD factor deficiency that were previously identified (small font) or that are identified in this work (large font) are shown along with regions of the carboxylase that are hydrophobic (gray bars) or that cross-link in vitro to propeptide or Glu-containing peptide.^42-44  (B-D) The alignment of carboxylases from evolutionarily distant organisms⁴⁵  is shown for sequences surrounding the residues (single-letter codes) whose mutations were identified in the proposita: Asp31Asn (B), Trp157Arg (C), and Thr591Lys (D). Residues that are identical or similar in all proteins are highlighted in black or gray, respectively.