You can find more information about ubiquitin-activating enzyme using the following links:

PFID PFID Old Formal Annotation PlasmoDB TDR Targets Subcellular Localization Affecting Drugs
Drug Name PubMed Articles (year of publication)
PF3D7_1333200 PF13_0182 ubiquitin-activating enzyme PlasmoDB TDR
Expasy - NiceZime View
Brenda - The Comprehensive Enzyme Information System