Making cow-free caseins and casein micelles

A key step in the precision fermentation of casein proteins is correct phosphorylation to generate one or more short linear sequence motifs (SLiMs) containing three or more phosphorylated seryl residues. The work of Balasubramanian et al. takes us a step closer to that goal by showing that two bacterial phosphokinases are promising alternatives to the mammalian Golgi phosphokinases and casein kinase-II.