6QVT:
reference: Unliganded and CMP-Neu5Ac bound structures of human alpha-2,6-sialyltransferase ST6Gal I at high resolution., Harrus D, Harduin-Lepers A, Glumoff T, J Struct Biol. 2020 Sep 21;212(2):107628. doi: 10.1016/j.jsb.2020.107628. PMID: 32971290

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).