Name	Info	Provider	Link
hchA	free resource	BioCyc	https://metacyc.org/gene?orgid=META&id=G7055
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=14731284.ui
	free resource	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0950-382X&date=2004&volume=51&issue=3&spage=849