Salt-driven equilibrium between two conformations in the HAMP domain from Natronomonas pharaonis - The language of signal transfer?

Autor(en): Doebber, Meike
Bordignon, Enrica
Klare, Johann P.
Holterhues, Julia
Martell, Swetlana
Mennes, Nadine
Li, Lin
Engelhard, Martin
Steinhoff, Heinz-Juergen 
Stichwörter: BACTERIORHODOPSIN; Biochemistry & Molecular Biology; COMPLEX; HISTIDINE KINASE; NITROXIDE MOTION; PHOBORHODOPSIN; PHOTOTRANSDUCER; SENSORY RHODOPSIN II; SIDE-CHAINS; SPIN-LABELED PROTEINS; STRUCTURAL DETERMINANTS
Erscheinungsdatum: 2008
Herausgeber: ELSEVIER
Journal: JOURNAL OF BIOLOGICAL CHEMISTRY
Volumen: 283
Ausgabe: 42
Startseite: 28691
Seitenende: 28701
Zusammenfassung: 
HAMP domains (conserved in histidine kinases, adenylyl cyclases, methyl-accepting chemotaxis proteins, and phosphatases) perform their putative function as signal transducing units in diversified environments in a variety of protein families. Here the conformational changes induced by environmental agents, namely salt and temperature, on the structure and function of a HAMP domain of the phototransducer from Natronomonas pharaonis (NpHtrII) in complex with sensory rhodopsin II (NpSRII) were investigated by site-directed spin labeling electron paramagnetic resonance. A series of spin labeled mutants were engineered in NpHtrII(157), a truncated analog containing only the first HAMP domain following the transmembrane helix 2. This truncated transducer is shown to be a valid model system for a signal transduction domain anchored to the transmembrane light sensor NpSRII. The HAMP domain is found to be engaged in a ``two-state'' equilibrium between a highly dynamic (dHAMP) and a more compact (cHAMP) conformation. The structural properties of the cHAMP as proven by mobility, accessibility, and intra-transducer-dimer distance data are in agreement with the four helical bundle NMR model of the HAMP domain from Archaeoglobus fulgidus.
DOI: 10.1074/jbc.M801931200

Show full item record

Page view(s)

2
Last Week
1
Last month
0
checked on Feb 23, 2024

Google ScholarTM

Check

Altmetric