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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Role of E270 in pH- and metal-sensitivities of firefly luciferases

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Author(s):
Viviani, V. R. [1, 2] ; Pelentir, G. F. [2] ; Oliveira, G. [1] ; Tomazini, A. [3] ; Bevilaqua, V. R. [1]
Total Authors: 5
Affiliation:
[1] Fed Univ Sao Carlos UFSCAR, Grad Program Evolut Genet & Mol Biol, Sao Carlos, SP - Brazil
[2] Fed Univ Sao Carlos UFSCar, Grad Program Biotechnol & Environm Monitoring, Rodovia Joao Leme dos Santos, Km 110, Sorocaba, SP - Brazil
[3] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Biorenewables Energy Natl Lab LNBR, Campinas, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES; v. 19, n. 11, p. 1548-1558, NOV 1 2020.
Web of Science Citations: 0
Abstract

Firefly luciferases display a typical change in bioluminescence color to red at acidic pH, high temperatures and in the presence of heavy metals. Recently, the proton and metal sensing site responsible for the pH-sensitivity of firefly luciferases, which involves the salt bridges between E311-R337 and H310-E354, was identified. However, it is unclear what other residues contribute to the distinct degrees of pH-sensitivity observed in other firefly luciferases. A multialignment of primary structures of a large set of pH-sensitive and pH-insensitive beetle luciferases showed that the conserved E270 among adult firefly luciferases is substituted by Gly (railroad worms)/Gln (click-beetles) in pH-insensitive ones. Site-directed mutagenesis studies using Macrolampis sp2 and Amydetes vivianii firefly luciferases indeed showed that E270 is important for the pH-dependent activity and spectral profiles: the substitution E270A/G drastically decreases the spectral pH-sensitivity, and extends the activity profile above pH 9.0. These mutations also decrease the sensitivity to metals such as zinc, mercury and cadmium. Modelling studies showed that the residue E270 is located in a three-glutamate motif (269EEE271) at the N-terminal of alpha-helix-10. The results suggest that at acidic pH, the protonation of E270 carboxylate may extend a turn of the helix at the N-terminal, misaligning the pH-sensor and luciferin phenolate binding site residues: S286, I288 and E311. In contrast, the substitution of E270A/G may unwind a turn of the alpha-helix-10, indirectly increasing the interaction of the pH-sensor and other residues at the bottom of the luciferin binding site, stabilizing the green light emitting conformation. (AU)

FAPESP's process: 10/05426-8 - Arthropod bioluminescence: biological diversity in Brazilian biomes, biochemical origin, structural/functional evolution of luciferases, molecular differentiation of lanterns, biotechnological, environmental and educational applications
Grantee:Vadim Viviani
Support Opportunities: Research Projects - Thematic Grants