CMP-sialic acid synthetase (NmCSS) is an essential enzyme involved in the biosynthesis of carbohydrates and glycoconjugates containing sialic acids. CMP-sialic acid synthetase (NmCSS) activates free Sia, converting it to CMP-Sia, which is the only donor substrate for all sialyltransferases.
References:
[1]. Wu D, et, al. A point-mutation in the C-domain of CMP-sialic acid synthetase leads to lethality of medaka due to protein insolubility. Sci Rep. 2021 Dec 1;11(1):23211.