The HagA precursor from strain 381 is 2600 aa in length. The hagA precursor from strain w83 is 2100 aa in length.

By choosing the different repeat block, HagA is divided to either 4 or 5 contiguous repeat blocks. However the four contiguous repeat blocks model agrees better with the cleavage site of this polyprotein *.

* Infect Immun 1996 Oct;64(10):4000-7 The hemagglutinin gene A (hagA) of Porphyromonas gingivalis 381 contains four large, contiguous, direct repeats.
Han N, Whitlock J, Progulske-Fox A