PDBsum entry: 2rm8

Signaling protein

PDB id: 2rm8

Contents

Protein chain

68 a.a. *

* Residue conservation analysis

PDB id:

2rm8

Name:

Signaling protein

Title:

The solution structure of phototactic transducer protein htrii linker region from natronomonas pharaonis

Structure:

Sensory rhodopsin ii transducer. Chain: a. Fragment: residues unp 100-159. Synonym: htr-ii, methyl-accepting phototaxis protein ii, mpp-ii. Engineered: yes

Source:

Natronomonas pharaonis. Organism_taxid: 2257. Gene: htrii. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

20 models

Authors:

K.Hayashi,Y.Sudo,J.Jee,M.Mishima,H.Hara,N.Kamo,C.Kojima

Key ref:

K.Hayashi et al. (2007). Structural Analysis of the Phototactic Transducer Protein HtrII Linker Region from Natronomonas pharaonis(,). Biochemistry, 46, 14380-14390. PubMed id: 18001143 DOI: 10.1021/bi701837n

Date:

15-Oct-07 Release date: 04-Dec-07

Protein chain

P42259  (HTR2_NATPH) -  Sensory rhodopsin II transducer

Seq: 534 a.a.

Struc: 68 a.a.*

* PDB and UniProt seqs differ at 8 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 

• Cellular component: integral to membrane (1 term)
• Biological process: signal transduction (1 term)
• Biochemical function: signal transducer activity (1 term)

DOI no: 10.1021/bi701837n

Biochemistry 46:14380-14390 (2007)

PubMed id: 18001143

Structural Analysis of the Phototactic Transducer Protein HtrII Linker Region from Natronomonas pharaonis(,).

K.Hayashi, Y.Sudo, J.Jee, M.Mishima, H.Hara, N.Kamo, C.Kojima.

ABSTRACT

Halobacterial pharaonis phoborhodopsin [ppR, also called Natronomonas pharaonis sensory rhodopsin II (NpSRII)] is a phototaxis protein which transmits a light signal to the cytoplasm through its transducer protein (pHtrII). pHtrII, a two-transmembrane protein that interacts with ppR, belongs to the group of methyl-accepting chemotaxis proteins (MCPs). Several mutation studies have indicated that the linker region connecting the transmembrane and methylation regions is necessary for signal transduction. However, the three-dimensional (3D) structure of an MCP linker region has yet to be reported, and hence, details concerning the signal transduction mechanism remain unknown. Here the structure of the pHtrII linker region was investigated biochemically and biophysically. Following limited proteolysis, only one trypsin resistant fragment in the pHtrII linker region was identified. This fragment forms a homodimer with a Kd value of 115 muM. The 3D structure of this fragment was determined by solution NMR, and only one alpha-helix was found between two HAMP domains of the linker region. This alpha-helix was significantly stabilized within transmembrane protein pHtrII as revealed by CW-EPR. The presence of Af1503 HAMP domain-like structures in the linker region was supported by CD, NMR, and ELDOR data. The alpha-helix determined here presumably works as a mechanical joint between two HAMP domains in the linker region to transfer the photoactivated conformational change downstream.