Inter-helical Hydrogen Bonds Are Essential Elements for Intra-protein Signal Transduction: The Role of Asp115 in Bacteriorhodopsin Transport Function

The behavior of the D115A mutant was analyzed by time-resolved UV-Vis and Fourier transformed infrared (FTIR) spectroscopies, aiming to clarify the role of Asp115 in the intra-protein signal transductions occurring during the bacteriorhodopsin photocycle. UV-Vis data on the D115A mutant show severel...

Full description

Saved in:
Bibliographic Details
Published in:Journal of molecular biology 2007-05, Vol.368 (3), p.666-676
Main Authors: Perálvarez-Marín, Alex, Lórenz-Fonfría, Víctor A., Bourdelande, José-Luís, Querol, Enric, Kandori, Hideki, Padrós, Esteve
Format: Article
Language:English
Subjects:
Amino Acid Motifs
Amino Acid Substitution
Aspartic Acid - chemistry
Aspartic Acid - genetics
bacteriorhodopsin
Bacteriorhodopsins - chemistry
Bacteriorhodopsins - genetics
Bacteriorhodopsins - physiology
Biologi
Biology
Cell and molecular biology
Cell- och molekylärbiologi
Halobacterium salinarum - metabolism
Halobacterium salinarum - radiation effects
Hydrogen Bonding
Light
membrane proteins
Models, Molecular
Molecular biology
Molekylärbiologi
NATURAL SCIENCES
NATURVETENSKAP
protein dynamics
Protein Structure, Secondary
Protein Transport
Purple Membrane - metabolism
Purple Membrane - radiation effects
Signal Transduction
Spectroscopy, Fourier Transform Infrared
time resolved spectroscopies
Water - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The behavior of the D115A mutant was analyzed by time-resolved UV-Vis and Fourier transformed infrared (FTIR) spectroscopies, aiming to clarify the role of Asp115 in the intra-protein signal transductions occurring during the bacteriorhodopsin photocycle. UV-Vis data on the D115A mutant show severely desynchronized photocycle kinetics. FTIR data show a poor transmission of the retinal isomerization to the chromoprotein, evidenced by strongly attenuated helical changes (amide I), the remarkable absence of environment alterations and protonation/deprotonation events related to Asp96 and direct Schiff base (SB) protonation form the bulk. This argues for the interactions of Asp115 with Leu87 (via water molecule) and Thr90 as key elements for the effective and vectorial proton path between Asp96 and the SB, in the cytoplasmic half of bacteriorhodopsin. The results strongly suggest the presence of a regulation motif enclosed in helices C and D (Thr90–Pro91/Asp115) which drives properly the dynamics of helix C through a set of interactions. It also supports the idea that intra-helical hydrogen bonding clusters in the buried regions of transmembrane proteins can be potential elements in intra-protein signal transduction.
ISSN:0022-2836
1089-8638
1089-8638
DOI:10.1016/j.jmb.2007.02.021