Mass spectrometry analysis and transcriptome sequencing reveal glowing squid crystal proteins are in the same superfamily as firefly luciferase.

ABSTRACT: The Japanese firefly squid Hotaru-ika (Watasenia scintillans) produces intense blue light from photophores at the tips of two arms. These photophores are densely packed with protein microcrystals that catalyse the bioluminescent reaction using ATP and the substrate coelenterazine disulfate. The squid is the only organism known to produce light using protein crystals. We extracted microcrystals from arm tip photophores and identified the constituent proteins using mass spectrometry and transcriptome libraries prepared from arm tip tissue. The crystals contain three proteins, wsluc1-3, all members of the ANL superfamily of adenylating enzymes. They share 19 to 21% sequence identity with firefly luciferases, which produce light using ATP and the unrelated firefly luciferin substrate. We propo

SUBMITTER: Gimenez G 

PROVIDER: S-EPMC4899746 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature