PDBsum entry 4q25

Unknown function

PDB id: 4q25

Contents

Protein chains

211 a.a.

Waters ×58

PDB id:

4q25

Name:

Unknown function

Title:

Crystal structure of phou from pseudomonas aeruginosa

Structure:

Phosphate-specific transport system accessory protein phou homolog. Chain: a, b. Synonym: pst system accessory protein phou homolog. Engineered: yes

Source:

Pseudomonas aeruginosa. Organism_taxid: 208964. Strain: pao1. Gene: pa5365, phou. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.28Å R-factor: 0.210 R-free: 0.234

Authors:

S.J.Lee,B.-J.Lee,S.W.Suh

Key ref:

S.J.Lee et al. (2014). Crystal structure of PhoU from Pseudomonas aeruginosa, a negative regulator of the Pho regulon. J Struct Biol, 188, 22-29. PubMed id: 25220976 DOI: 10.1016/j.jsb.2014.08.010

Date:

07-Apr-14 Release date: 18-Feb-15

Protein chains

Q51547  (PHOU_PSEAE) -  Phosphate-specific transport system accessory protein PhoU homolog from Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)

Seq: 242 a.a.

Struc: 211 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1016/j.jsb.2014.08.010

J Struct Biol 188:22-29 (2014)

PubMed id: 25220976

Crystal structure of PhoU from Pseudomonas aeruginosa, a negative regulator of the Pho regulon.

S.J.Lee, Y.S.Park, S.J.Kim, B.J.Lee, S.W.Suh.

ABSTRACT

In Escherichia coli, seven genes (pstS, pstC, pstA, pstB, phoU, phoR, and phoB) are involved in sensing environmental phosphate (Pi) and controlling the expression of the Pho regulon. PhoU is a negative regulator of the Pi-signaling pathway and modulates Pi transport through Pi transporter proteins (PstS, PstC, PstA, and PstB) through the two-component system PhoR and PhoB. Inactivation of PhoY2, one of the two PhoU homologs in Mycobacterium tuberculosis, causes defects in persistence phenotypes and increased susceptibility to antibiotics and stresses. Despite the important biological role, the mechanism of PhoU function is still unknown. Here we have determined the crystal structure of PhoU from Pseudomonas aeruginosa. It exists as a dimer in the crystal, with each monomer consisting of two structurally similar three-helix bundles. Our equilibrium sedimentation measurements support the reversible monomer-dimer equilibrium model in which P. aeruginosa PhoU exists in solution predominantly as dimers, with monomers in a minor fraction, at low protein concentrations. The dissociation constant for PhoU dimerization is 3.2×10(-6)M. The overall structure of P. aeruginosa PhoU dimer resembles those of Aquifex aeolicus PhoU and Thermotoga maritima PhoU2. However, it shows distinct structural features in some loops and the dimerization pattern.