Fig. 3: Biochemical characterization of Bcs3.
From: A multi-enzyme machine polymerizes the Haemophilus influenzae type b capsule
a, Schematic representation of a multiple-sequences alignment to highlight important amino acid residues and structural elements. Distantly related hits (26–24% identity) from a BLAST21 search of Bcs3 are shown. An amino acid stretch unique to Bcs3 in the depicted alignment and starting with Q629 was identified and used to separate the predicted CrpP from the CriT domain. b, Overview of Bcs3 constructs generated in this study. Truncation constructs 21–24 were generated based on the homologs identified in E. coli K18, which expresses CroT as a separate polypeptide. X, amino acid exchanges to alanine; the domains are colored according to Fig. 3a. See also Supplementary Fig. 10. c–f, PAGE analysis of reactions containing the purified construct(s) (Supplementary Fig. 2) as indicated in b. Polymers were visualized using Alcian blue18. Constructs are numbered, as shown in Fig. 3a. a, acceptor (pool 3, Extended Data Fig. 7k).
