Bioluminescence Is Produced from a Trapped Firefly Luciferase Conformation Predicted by the Domain Alternation Mechanism
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- 作者：Bruce R. Branchini ; Justin C. Rosenberg ; Danielle M. Fontaine ; Tara L. Southworth ; Curran E. Behney ; Lerna Uzasci
- 刊名：Journal of the American Chemical Society
- 出版年：2011
- 出版时间：July 27, 2011
- 年：2011
- 卷：133
- 期：29
- 页码：11088-11091
- 全文大小：763K
- 年卷期：v.133,no.29(July 27, 2011)
- ISSN：1520-5126
文摘
According to the domain alternation mechanism and crystal structure evidence, the acyl-CoA synthetases, one of three subgroups of a superfamily of adenylating enzymes, catalyze adenylate- and thioester-forming half-reactions in two different conformations. The enzymes accomplish this by presenting two active sites through an 140掳 rotation of the C-domain. The second half-reaction catalyzed by another subgroup, the beetle luciferases, is a mechanistically dissimilar oxidative process that produces bioluminescence. We have demonstrated that a firefly luciferase variant containing cysteine residues at positions 108 and 447 can be intramolecularly cross-linked by 1,2-bis(maleimido)ethane, trapping the enzyme in a C-domain-rotated conformation previously undocumented in the available luciferase crystal structures. The cross-linked luciferase cannot adenylate luciferin but is nearly fully capable of bioluminescence with synthetic luciferyl adenylate because it retains the ability to carry out the oxidative half-reaction. The cross-linked luciferase is apparently trapped in a conformation similar to those adopted by acyl-CoA synthetases as they convert acyl adenylates into the corresponding CoA thioesters.