Table 2.
Francisella group | Chitinase class | Predicted pseudogenea | Recombinant activity | In vitro production |
---|---|---|---|---|
F. tularensis | ||||
A1a/A1b | ChiA | No | + | + |
ChiB | No* | + | – | |
ChiC | Yes/Yes† | –/+ | – | |
ChiD | No | – | NTb | |
A2 | ChiA | Yes‡ | NT | – |
ChiB | Yes§ | NT | – | |
ChiC | No | + | + | |
ChiD | No | – | NT | |
Type B | ChiA | No | + | + |
ChiB | No | + | + | |
ChiC | No¶ | – | – | |
ChiD | No | – | NT | |
F. novicida | ChiA | No | + | + |
ChiB | No | + | + | |
ChiC | No# | NT | – | |
ChiD | No | – | NT |
The pseudogene designation is based on existing notations made to the annotated genome sequences. *, F. tularensis A1a/A1b ChiB has an N-terminal truncation resulting in deletion of the signal peptide and the N-acetylglucosamine-binding protein A domain but does not impact the GH18 domain. †, F. tularensis A1a/A1b chiC contains a point mutation that causes a premature stop codon and results in two predicted open reading frames. One reading frame (FTT_1592c) encodes an unaltered GH18 domain. ‡, F. tularensis A2 chiA is truncated due to a mutation resulting in a premature stop codon; the GH18 domain is missing. §, F. tularensis A2 chiB is truncated due to a mutation resulting in a premature stop codon; the GH18 domain is missing. ¶, F. tularensis type B ChiC contains a C-terminal truncation of that impacts the GH18 domain, but its gene is not annotated as a pseudogene. #, F. novicida strain GA99-3550 did not encode chiC. However, F. novicida GA99-3548 encoded a chiC whose product was predicted functional.
NT, not tested.