Model of the Active Site of Firefly Luciferase

T. P. Sandalova¹ and N. N. Ugarova^2*

¹Institute of Biophysics, Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, 660036 Russia; and Karolinska Institut, Stockholm, 17177 Sweden

²School of Chemistry, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-5417; E-mail: unn@enzyme.chem.msu.ru

^* To whom correspondence should be addressed.

Received December 24, 1998

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A model for the spatial structure of firefly luciferase--ATP--luciferin complex is suggested using the coordinates of unliganded luciferase and the enzyme--substrate complex of the adenylating subunit of gramicidin S synthetase known from the literature. Conformational changes in luciferase can occur during substrate binding resulting in a relative orientation of two luciferase domains similar to that in case of the AMP--phenylalanine--synthetase complex. The model is consistent with data on the physicochemical properties of firefly luciferase and its complexes with the substrates.

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KEY WORDS: bioluminescence, firefly luciferase, ATP, luciferin, spatial structure, active site, enzyme--substrate complex

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