PDBsum entry 6faq

DNA binding protein

PDB id: 6faq

Contents

Protein chains

110 a.a.

Ligands

SO4

Metals

_BR ×22

Waters ×189

PDB id:

6faq

Name:

DNA binding protein

Title:

Structure of h. Salinarum rosr (vng0258) grown from kbr

Structure:

DNA binding protein. Chain: a, b. Engineered: yes. Other_details: halophilic winged-helix-turn-helix DNA binding protein from h. Salinarum

Source:

Halobacterium salinarum (strain atcc 700922 / jcm 11081 / nrc-1). Halobacterium halobium. Organism_taxid: 64091. Atcc: 700922. Gene: vng_0258h. Expressed in: haloferax volcanii. Expression_system_taxid: 2246.

Resolution:

1.95Å R-factor: 0.191 R-free: 0.236

Authors:

B.Shaanan,N.Kutnowski

Key ref:

N.Kutnowski et al. (2018). The 3-D structure of VNG0258H/RosR - A haloarchaeal DNA-binding protein in its ionic shell. J Struct Biol, 204, 191-198. PubMed id: 30110657 DOI: 10.1016/j.jsb.2018.08.008

Date:

16-Dec-17 Release date: 22-Aug-18

Protein chains

Q9HSF4  (Q9HSF4_HALSA) -  PadR family transcription regulator RosR from Halobacterium salinarum (strain ATCC 700922 / JCM 11081 / NRC-1)

Seq: 116 a.a.

Struc: 110 a.a.

DOI no: 10.1016/j.jsb.2018.08.008

J Struct Biol 204:191-198 (2018)

PubMed id: 30110657

The 3-D structure of VNG0258H/RosR - A haloarchaeal DNA-binding protein in its ionic shell.

N.Kutnowski, H.Shmuely, I.Dahan, F.Shmulevich, G.Davidov, A.Shahar, J.Eichler, R.Zarivach, B.Shaanan.

ABSTRACT

Protein-DNA interactions are highly dependent on salt concentration. To gain insight into how such interactions are maintained in the highly saline cytoplasm of halophilic archaea, we determined the 3-D structure of VNG0258H/RosR, the first haloarchaeal DNA-binding protein from the extreme halophilic archaeon Halobactrium salinarum. It is a dimeric winged-helix-turn-helix (wHTH) protein with unique features due to adaptation to the halophilic environment. As ions are major players in DNA binding processes, particularly in halophilic environments, we investigated the solution structure of the ionic envelope and located anions in the first shell around the protein in the crystal using anomalous scattering. Anions that were found to be tightly bound to residues in the positively charged DNA-binding site would probably be released upon DNA binding and will thus make significant contribution to the driving force of the binding process. Unexpectedly, ions were also found in a buried internal cavity connected to the external medium by a tunnel. Our structure lays a solid groundwork for future structural, computational and biochemical studies on complexes of the protein with cognate DNA sequences, with implications to protein-DNA interactions in hyper-saline environments.