PDBsum entry 4hj3

Signaling protein

PDB id: 4hj3

Contents

Protein chains

175 a.a.

Ligands

FMN ×2

Waters ×41

PDB id:

4hj3

Name:

Signaling protein

Title:

Crystal structure of rhodobacter sphaeroides lov protein

Structure:

Lov protein. Chain: a, b. Engineered: yes. Mutation: yes

Source:

Rhodobacter sphaeroides. Organism_taxid: 349102. Strain: atcc 17025. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.64Å R-factor: 0.196 R-free: 0.240

Authors:

B.R.Crane,K.S.Conrad,A.M.Bilwes

Key ref:

K.S.Conrad et al. (2013). Light-induced subunit dissociation by a light-oxygen-voltage domain photoreceptor from Rhodobacter sphaeroides. Biochemistry, 52, 378-391. PubMed id: 23252338

Date:

12-Oct-12 Release date: 16-Jan-13

Protein chains

M1E1F9  (M1E1F9_CERS5) -  LOV protein from Cereibacter sphaeroides (strain ATCC 17025 / ATH 2.4.3)

Seq: 176 a.a.

Struc: 175 a.a.

Biochemistry 52:378-391 (2013)

PubMed id: 23252338

Light-induced subunit dissociation by a light-oxygen-voltage domain photoreceptor from Rhodobacter sphaeroides.

K.S.Conrad, A.M.Bilwes, B.R.Crane.

ABSTRACT

Light-oxygen-voltage (LOV) domains bind a flavin chromophore to serve as blue light sensors in a wide range of eukaryotic and prokaryotic proteins. LOV domains are associated with a variable effector domain or a separate protein signaling partner to execute a wide variety of functions that include regulation of kinases, generation of anti-sigma factor antagonists, and regulation of circadian clocks. Here we present the crystal structure, photocycle kinetics, association properties, and spectroscopic features of a full-length LOV domain protein from Rhodobacter sphaeroides (RsLOV). RsLOV exhibits N- and C-terminal helical extensions that form an unusual helical bundle at its dimer interface with some resemblance to the helical transducer of sensory rhodopsin II. The blue light-induced conformational changes of RsLOV revealed from a comparison of light- and dark-state crystal structures support a shared signaling mechanism of LOV domain proteins that originates with the light-induced formation of a flavin-cysteinyl photoadduct. Adduct formation disrupts hydrogen bonding in the active site and propagates structural changes through the LOV domain core to the N- and C-terminal extensions. Single-residue variants in the active site and dimer interface of RsLOV alter photoadduct lifetimes and induce structural changes that perturb the oligomeric state. Size exclusion chromatography, multiangle light scattering, small-angle X-ray scattering, and cross-linking studies indicate that RsLOV dimerizes in the dark but, upon light excitation, dissociates into monomers. This light-induced switch in oligomeric state may prove to be useful for engineering molecular associations in controlled cellular settings.