The influence of the loop between residues 223-235 in beetle luciferase bioluminescence spectra: A solvent gate for the active site of pH-sensitive luciferases
MetadataShow full item record
Beetle luciferases emit a wide range of bioluminescence colors, ranging from green to red. Firefly luciferases can shift the spectrum to red in response to pH and temperature changes, whereas click beetle and railroadworm luciferases do not. Despite many studies on firefly luciferases, the origin of pH-sensitivity is far from being understood. Through comparative site-directed mutagenesis and modeling studies, using the pH-sensitive luciferases (Macrolampis and Cratomorphus distinctus fireflies) and the pH-insensitive luciferases (Pyrearinus termitilluminans, Phrixotrix viviani and Phrixotrix hirtus) cloned by our group, here we show that substitutions dramatically affecting bioluminescence colors in both groups of luciferases are clustered in the loop between residues 223-235 (Photinus pyralis sequence). The substitutions at positions 227, 228 and 229 (P. pyralis sequence) cause dramatic redshift and temporal shift in both groups of luciferases, indicating their involvement in labile interactions. Modeling studies showed that the residues Y227 and N229 are buried in the protein core, fixing the loop to other structural elements participating at the bottom of the luciferin binding site. Changes in pH and temperature (in firefly luciferases), as well as point mutations in this loop, may disrupt the interactions of these structural elements exposing the active site and modulating bioluminescence colors. © 2007 The Authors.
How to cite this document
Showing items related by title, author, creator and subject.
Miziara, Melissa Nunes ; Riggs, Penny K.; Amaral, M. Elisabete J. (Genetics and Molecular Research, 2004) [Trabalho apresentado em evento]Genomic sequence comparison across species has enabled the elucidation of important coding and regulatory sequences encoded within DNA. Of particular interest are the noncoding regulatory sequences, which influence gene ...
Caroci, A. S.; Calvo, E.; Ribolla, P. E. ; De Bianchi, A. G.; Marinotti, O. (Journal of Medical Entomology, 2003) [Artigo]Trypsin activity increases in the midgut of Anopheles aquasalis, Anopheles albitarsis, and Anopheles darlingi after a bloodmeal. The activity returns to basal levels at the time the blood is completely digested. Affinity ...
Almeida, L. M. ; Amaral, M. E J ; Silva, I. T.; Silva, W. A.; Riggs, P. K.; Carareto, C. M. (Genetics and Molecular Research, 2008) [Artigo]Despite the wide distribution of transposable elements (TEs) in mammalian genomes, part of their evolutionary significance remains to be discovered. Today there is a substantial amount of evidence showing that TEs are ...