Looking at the NHase from Monosiga brevicollis

I have been looking at the sequence for the single subunit NHase from the eukaryote Monosiga brevicollis. There are four things that spring to mind of interest:
1. The thing has joined the two prokaryotic subunits together in the fashion B to A.
2. The usual signature bit of the sequence says it is a cobalt centred NHase, and the alpha subunit is very similar to that shown by the two cobalt centred NHases with pdb files 1V29 and 1UGP.

 3. The joint between the alpha and beta subunits has a LOT of histidines in it, which explains why it took a long time to come off the nickel affinity column!

4. The surface loop which is nice differentiating feature between cobalt-centred and iron centred NHase (which dont have it) is very different with this beast. The picture below is of 1V29, with the loop indicated.