The structural origin of the color differences in the bioluminescence of firefly luciferase.

Six chimeric mutants between Hotaria parvula (lambda max = 568 nm) and Pyrocoelia miyako (lambda max = 550 nm) luciferases were reconstructed to determine the structural origin of the color differences in firefly luciferase. Based on light-emitting color, five chimeric luciferases could be divided into two groups: the three green-emitting mutants, classified as P. miyako luciferase, and the two yellow-emitting mutants, classified as H. parvula luciferase. Their common fragments between Val-209 and Ala-318 within each group contain the active site for the color differences.