PDBsum entry 1el4

Luminescent protein

PDB id: 1el4

Contents

Protein chain

194 a.a. *

Ligands

CTZ

Metals

_CL

Waters ×266

* Residue conservation analysis

References listed in PDB file

Key reference

• Title: Structure of the ca2+-Regulated photoprotein obelin at 1.7 a resolution determined directly from its sulfur substructure.
• Authors: Z.J.Liu, E.S.Vysotski, C.J.Chen, J.P.Rose, J.Lee, B.C.Wang.
• Ref.: Protein Sci, 2000, 9, 2085-2093. [DOI no: 10.1110/ps.9.11.2085]
• PubMed id: 11152120

Abstract

The crystal structure of the photoprotein obelin (22.2 kDa) from Obelia longissima has been determined and refined to 1.7 A resolution. Contrary to the prediction of a peroxide, the noncovalently bound substrate, coelenterazine, has only a single oxygen atom bound at the C2-position. The protein-coelenterazine 2-oxy complex observed in the crystals is photo-active because, in the presence of calcium ion, bioluminescence emission within the crystal is observed. This structure represents only the second de novo protein structure determined using the anomalous scattering signal of the sulfur substructure in the crystal. The method used here is theoretically different from that used for crambin in 1981 (4.72 kDa) and represents a significant advancement in protein crystal structure determination.

Secondary reference #1

• Title: Preparation and preliminary study of crystals of the recombinant calcium-Regulated photoprotein obelin from the bioluminescent hydroid obelia longissima.
• Authors: E.S.Vysotski, Z.J.Liu, J.Rose, B.C.Wang, J.Lee.
• Ref.: Acta Crystallogr D Biol Crystallogr, 1999, 55, 1965-1966. [DOI no: 10.1107/S0907444999011828]
• PubMed id: 10531510

Figure 1.
Figure 1 Crystal of the photoprotein obelin, grown from 1.4 M sodium citrate. Approximate dimensions are 0.1 × 0.1 × 1.0 mm.

The above figure is reproduced from the cited reference with permission from the IUCr