Name	Info	Provider	Link
purB	free resource	BioCyc	https://ecocyc.org/gene?orgid=ECOLI&id=EG11314
	subscription/membership/fee required	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/S0022-2836(07)00545-1
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/17531264/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/17531264
	free resource	NCI CPTAC Assay Portal	https://assays.cancer.gov/non-CPTAC-1105