PDBsum entry 2y8h

Transferase

PDB id: 2y8h

Contents

Protein chains

152 a.a. *

Ligands

HEM ×2

Metals

_CA

Waters ×308

* Residue conservation analysis

PDB id:

2y8h

Name:

Transferase

Title:

Structure of the first gaf domain e87g mutant of mycobacterium tuberculosis doss

Structure:

Two component sensor histidine kinase devs. Chain: a, b. Fragment: gaf domain, residues 63-210. Synonym: two component sensor histidine kinase doss. Engineered: yes. Mutation: yes. Other_details: d63 to k210 of doss with additional gamdp

Source:

Mycobacterium tuberculosis. Organism_taxid: 83332. Strain: h37rv. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

1.90Å R-factor: 0.212 R-free: 0.256

Authors:

H.Y.Cho,H.J.Cho,B.S.Kang

Key ref:

H.Y.Cho et al. (2011). Blockage of the channel to heme by the E87 side chain in the GAF domain of Mycobacterium tuberculosis DosS confers the unique sensitivity of DosS to oxygen. Febs Lett, 585, 1873-1878. PubMed id: 21536032

Date:

07-Feb-11 Release date: 23-Feb-11

Protein chains

P9WGK3  (DEVS_MYCTU) -  Oxygen sensor histidine kinase response regulator DevS/DosS from Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)

Seq: 578 a.a.

Struc: 152 a.a.*

* PDB and UniProt seqs differ at 6 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.2.7.13.3 - histidine kinase.
• Reaction: ATP + protein L-histidine = ADP + protein N-phospho-L-histidine

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

Febs Lett 585:1873-1878 (2011)

PubMed id: 21536032

Blockage of the channel to heme by the E87 side chain in the GAF domain of Mycobacterium tuberculosis DosS confers the unique sensitivity of DosS to oxygen.

H.Y.Cho, H.J.Cho, M.H.Kim, B.S.Kang.

ABSTRACT

Two sensor kinases, DosS and DosT, are responsible for recognition of hypoxia in Mycobacterium tuberculosis. Both proteins are structurally similar to each other, but DosS is a redox sensor while DosT binds oxygen. The primary difference between the two proteins is the channel to the heme present in their GAF domains. DosS has a channel that is blocked by E87 while DosT has an open channel. Absorption spectra of DosS mutants with an open channel show that they bind oxygen as DosT does when they are exposed to air, while DosT G85E mutant is oxidized similarly to DosS without formation of an oxy-ferrous form. This suggests that oxygen accessibility to heme is the primary factor governing the oxygen-binding properties of these proteins.