Opisthokonts, choanoflagellata and nitrile hydratases

There is an ongoing project called "The Origins of Multicellularity" which involves Gertraud Burger (University of Montreal, Canada), Michael W. Gray (Dalhousie University, Canada), Peter Holland, (University of Oxford, UK), Nicole King (University of California Berkeley, USA), B. Franz Lang (University of Montreal, Canada), Andrew Roger (Dalhousie University, Canada) and Iñaki Ruiz-Trillo (University of Barcelona, Spain) which seeks to investigate commonalities and differences underlying multicellularity in animals and fungi (to use their phrase). As I understand it, the idea is to take a range of simple organisms which go by the name of “opisthokonts” (which sounds quite unsavoury if said in a Dublin Irish accent) and use genomic analysis to track down features of a proposed eukaryotic ancestor, and propose how evolutionary pathways have lead to fungi and animals. These episothokonts are the sort of miniscule organisms the existence of which are not exactly common knowledge, and hence come with names that make bacterial monikers seem easy to remember. Here is a tree of the organisms this project are looking at- those in blue bold type are those which the genomes the project is working on. 

One subset of the opisothokonts are the choanoflagellata, and it contains both Monsiga brevicollis and Salpingoeca rosetta both of which have a single chain NHase.  The genome data from the project is going up online as it is produced so NCBI searching works well for making BLASTp type comparisions. I have had a good go at working through the organisms listed on this tree, BLASTp both the beta/alpha single chain NHase from Monsiga brevicollis and the alpha chain from CGA009, and I cannot find anything meaningful in anything apart from Salpingoeca rosetta, which I found interesting. So there are nothing NHase-like in the fungi taxid, nothing in filasterea or ichthyosporea AND nothing in the genome for Monosiga ovata (which seems to have had a bit of a chequered history with impurity issues). That last fact seems weird to me but I even tried using BLASTp with a section of the beta like chain of Monsiga brevicollis  (just in case there was more exon/intron messing about going on, as the authors of the original Monsiga brevicollis paper identified, that I hadn't picked up on) and still nothing of consequence. (Diagram below from this paper).

It makes me wonder why just these organisms carry something like a functional NHase… there must be some evolutionary reason.