PDBsum entry 6pru

Signaling protein

PDB id: 6pru

Contents

Protein chains

150 a.a.

Ligands

VRB ×2

EDO ×7

PEG

Metals

_CL ×10

_MG ×4

Waters ×338

PDB id:

6pru

Name:

Signaling protein

Title:

Photoconvertible crystals of pixj from thermosynechococcus elongatus

Structure:

Methyl-accepting chemotaxis protein. Chain: a, b. Fragment: gaf domain. Engineered: yes. Mutation: yes

Source:

Thermosynechococcus elongatus (strain bp-1). Organism_taxid: 197221. Strain: bp-1. Gene: tll0569. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.54Å R-factor: 0.165 R-free: 0.207

Authors:

E.S.Burgie,J.A.Clinger,M.D.Miller,G.N.Phillips Jr.,R.D.Vierstra

Key ref:

E.S.Burgie et al. (2020). Photoreversible interconversion of a phytochrome photosensory module in the crystalline state. Proc Natl Acad Sci U S A, 117, 300-307. PubMed id: 31852825 DOI: 10.1073/pnas.1912041116

Date:

11-Jul-19 Release date: 18-Dec-19

Protein chains

Q8DLC7  (Q8DLC7_THEEB) -  Methyl-accepting chemotaxis protein from Thermosynechococcus vestitus (strain NIES-2133 / IAM M-273 / BP-1)

Seq: 940 a.a.

Struc: 150 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1073/pnas.1912041116

Proc Natl Acad Sci U S A 117:300-307 (2020)

PubMed id: 31852825

Photoreversible interconversion of a phytochrome photosensory module in the crystalline state.

E.S.Burgie, J.A.Clinger, M.D.Miller, A.S.Brewster, P.Aller, A.Butryn, F.D.Fuller, S.Gul, I.D.Young, C.C.Pham, I.S.Kim, A.Bhowmick, L.J.O'Riordan, K.D.Sutherlin, J.V.Heinemann, A.Batyuk, R.Alonso-Mori, M.S.Hunter, J.E.Koglin, J.Yano, V.K.Yachandra, N.K.Sauter, A.E.Cohen, J.Kern, A.M.Orville, G.N.Phillips, R.D.Vierstra.

ABSTRACT

A major barrier to defining the structural intermediates that arise during the reversible photointerconversion of phytochromes between their biologically inactive and active states has been the lack of crystals that faithfully undergo this transition within the crystal lattice. Here, we describe a crystalline form of the cyclic GMP phosphodiesterases/adenylyl cyclase/FhlA (GAF) domain from the cyanobacteriochrome PixJ in Thermosynechococcus elongatus assembled with phycocyanobilin that permits reversible photoconversion between the blue light-absorbing Pb and green light-absorbing Pg states, as well as thermal reversion of Pg back to Pb. The X-ray crystallographic structure of Pb matches previous models, including autocatalytic conversion of phycocyanobilin to phycoviolobilin upon binding and its tandem thioether linkage to the GAF domain. Cryocrystallography at 150 K, which compared diffraction data from a single crystal as Pb or after irradiation with blue light, detected photoconversion product(s) based on F_obs - F_obs difference maps that were consistent with rotation of the bonds connecting pyrrole rings C and D. Further spectroscopic analyses showed that phycoviolobilin is susceptible to X-ray radiation damage, especially as Pg, during single-crystal X-ray diffraction analyses, which could complicate fine mapping of the various intermediate states. Fortunately, we found that PixJ crystals are amenable to serial femtosecond crystallography (SFX) analyses using X-ray free-electron lasers (XFELs). As proof of principle, we solved by room temperature SFX the GAF domain structure of Pb to 1.55-Å resolution, which was strongly congruent with synchrotron-based models. Analysis of these crystals by SFX should now enable structural characterization of the early events that drive phytochrome photoconversion.