Firefly luciferase
= Firefly luciferase
A luminescent reporter <enzyme> whose output can report <promoter> activity under controlled expression and assay conditions.
Its light-producing reaction uses luciferin, <oxygen> and <ATP>, allowing chemical turnover to generate a detectable <photon> signal. <ATP> availability and <enzyme> abundance can both affect output, so <light> intensity does not uniquely measure <transcription> without appropriate normalization. <Enzyme Nomenclature by the IUBMB>[EC 1.13.12.7, reaction and comments]{ref}