2c7l

From Proteopedia

Revision as of 15:56, 5 November 2007

LOW TEMPERATURE STRUCTURE OF PHYCOERYTHROCYANIN FROM MASTIGOCLADUS LAMINOSUS

Overview

Phycoerythrocyanin is the only cyanobacterial phycobiliprotein containing, phycoviolobilin as a chromophore. The phycoviolobilin chromophore is, photo-reactive; upon irradiation, the chromophore undergoes a, Z/E-isomerization involving the rotation of pyrrole-ring D. We have, determined the structure of trimeric phycoerythrocyanin at three different, experimental settings: monochromatically at 110 K and 295 K as well as, with the Laue method at 288 K. Based on their chemical structures, the, restraints for the phycoviolobilin of the alpha-subunit and for the, phycocyanobilin chromophores of the beta-subunit were newly generated, which allows a chemically meaningful refinement of both chromophores. All, three phycoerythrocyanin structures are very similar; the subunits match, within 0.5 A. The detailed comparison of the data obtained with the, different measurements provided information about the protein properties, around the phycoviolobilin chromophore. For the first time, crystals of a, phycobilisome protein are used successfully with the Laue technique. This, paves the way for time-resolved macromolecular crystallography, which is, able to elucidate the exact mechanisms of the phycoviolobilin, photoactivity including the protein involvement.

About this Structure

2C7L is a Protein complex structure of sequences from Mastigocladus laminosus with BLA and CYC as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.

Reference

Local protein flexibility as a prerequisite for reversible chromophore isomerization in alpha-phycoerythrocyanin., Schmidt M, Krasselt A, Reuter W, Biochim Biophys Acta. 2006 Jan;1764(1):55-62. Epub 2005 Nov 21. PMID:16377266

Page seeded by OCA on Mon Nov 5 18:01:21 2007