<p> This family contains HypE (or HupE), a protein required for expression of catalytically active hydrogenase in many systems. It appears to be an accessory protein involved in maturation rather than a regulatory protein involved in expression. HypE shows considerable homology to the thiamine-monophosphate kinase ThiL (<db_xref db="INTERPRO" dbkey="IPR006283"/>) and other enzymes.</p> Hydrogenase expression/formation protein HypE