so fyi I worked in that lab, we called many of them MUFs ("membrane proteins of unknown functions")... We kind of suspect that all they do is maintain membrane integrity and isotonicity just by being present. One easy way for a cell to do to increase the yield of a stuff is to have literally more genes.

So there are a lot of interesting things to do (which I don't know if they did), like instead of having those last five genes in there, copying one of those five genes five times...