Article info 2018 6 (3)    006  (03)   pp.  51 ~ 55
Title X-ray crystallographic studies of a fluorescent protein Akane1 from Scleronephthya gracillimum
Authors So Eun Kim1, Kwang Yeon Hwang1* and Ki Hyun Nam1, 2*
Institutions 1Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea, 2Institute of Life Science and Natural Resources, Korea University, Seoul 02841, Republic of Korea *Correspondence: chahong@korea.ac.kr, structures@korea.ac.kr
Abstract Fluorescent proteins (FPs) are popular tools used to monitor the localization of a biomolecule and its interaction (in vivo or in vitro). Changes in fluorescence intensity caused by environmental elements (e.g. protons or metals) form the basis for the development of pH indicators or metal biosensors. FPs are constantly being engineered or discovered for efficient and extended applications. In this study, we report the expression, purification, characterization, crystallization, and preliminary X-ray diffraction studies of a fluorescent protein Akane1 from Scleronephthya gracillimum. This protein exhibited a dimeric state in solution. According to the spectral analysis, Akane1 showed excitation and emission maxima peaks at 501 and 510 nm, respectively. The crystals of Akane1 were obtained under a reservoir solution containing 100 mM Tris-HCl (pH 7.0), 200 mM calcium acetate, and 20% (w/v) PEG 3000. The crystals of Akane1 diffracted to 1.93 Å and belonged to the space group P21, with unit cell parameters of a = 56.02 Å, b = 126.67 Å, c = 62.03 Å, and β = 107.52°. The initial phase of Akane1 was obtained by the molecular replacement method.