PDBsum entry: 2koi

Transferase

PDB id: 2koi

Contents

Protein chain

172 a.a. *

Ligands

CYC

* Residue conservation analysis

PDB id:

2koi

Name:

Transferase

Title:

Refined solution structure of a cyanobacterial phytochrome g in the red light-absorbing ground state

Structure:

Sensor protein. Chain: a. Fragment: gaf domain (unp residues 31-200). Synonym: syb-cph1(gaf). Engineered: yes

Source:

Synechococcus sp.. Organism_taxid: 321332. Strain: ja-2-3b'a(2-13). Gene: cyb_2465. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

20 models

Authors:

C.C.Cornilescu,G.Cornilescu,A.T.Ulijasz,R.D.Vierstra,J.L.Mar Center For Eukaryotic Structural Genomics (Cesg)

Key ref:

A.T.Ulijasz et al. (2010). Structural basis for the photoconversion of a phytochrome to the activated Pfr form. Nature, 463, 250-254. PubMed id: 20075921 DOI: 10.1038/nature08671

Date:

22-Sep-09 Release date: 03-Nov-09

Protein chain

Q2JIZ5  (Q2JIZ5_SYNJB) -  Sensor histidine kinase

Seq: 834 a.a.

Struc: 172 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 

• Biological process: detection of visible light (3 terms)
• Biochemical function: protein binding (2 terms)

DOI no: 10.1038/nature08671

Nature 463:250-254 (2010)

PubMed id: 20075921

Structural basis for the photoconversion of a phytochrome to the activated Pfr form.

A.T.Ulijasz, G.Cornilescu, C.C.Cornilescu, J.Zhang, M.Rivera, J.L.Markley, R.D.Vierstra.

ABSTRACT

Phytochromes are a collection of bilin-containing photoreceptors that regulate numerous photoresponses in plants and microorganisms through their ability to photointerconvert between a red-light-absorbing, ground state (Pr) and a far-red-light-absorbing, photoactivated state (Pfr). Although the structures of several phytochromes as Pr have been determined, little is known about the structure of Pfr and how it initiates signalling. Here we describe the three-dimensional solution structure of the bilin-binding domain as Pfr, using the cyanobacterial phytochrome from Synechococcus OSB'. Contrary to predictions, light-induced rotation of the A pyrrole ring but not the D ring is the primary motion of the chromophore during photoconversion. Subsequent rearrangements within the protein then affect intradomain and interdomain contact sites within the phytochrome dimer. On the basis of our models, we propose that phytochromes act by propagating reversible light-driven conformational changes in the bilin to altered contacts between the adjacent output domains, which in most phytochromes direct differential phosphotransfer.